Bloons TD 6

"The Bloons are back and better than ever! Get ready for a massive 3D tower defense game designed to give you hours and hours of the best strategy gaming available. Craft your perfect defense from a combination of awesome monkey towers, upgrades, Heroes, and activated abilities, then pop every last Bloon that comes your way!"

- Ninja Kiwi

Bloons TD 6 (fully: Bloons Tower Defense 6, abbreviated: BTD6) is the latest installment and current flagship title of the Bloons Tower Defense series, developed and published by Ninja Kiwi. The game was released on June 13, 2018 for Android and iOS, and later brought to Steam for Windows and Macintosh. Like other tower defense games, including those in the BTD series, the objective of Bloons TD 6 is to prevent enemy balloons, referred to as "Bloons", from traversing a track and taking lives. The player achieves this by using a combination of monkey-based towers to pop the Bloons before they can escape. As a sequel to Bloons TD 5 and its generational spinoffs, Bloons TD 6 introduces 3D graphics, line-of-sight mechanics, additional Bloon types (specifically the Purple Bloon, the Fortified property, and the Big Airship of Doom), Heroes, 5th-tier upgrades, a third upgrade path, expanded cosmetics, and more.

Major updates to Bloons TD 6 usually focus on implementing balance changes to towers, at 1 new map and other exclusive content. This includes the addition of new Heroes, weekly events, public profiles, and Paragons.

Three new towers were added after the games initial release: the Mortar Monkey (v6.0), Engineer Monkey (v12.0), and Dartling Gunner (v22.0). Many features from Bloons TD 5 Mobile and Bloons Monkey City also return, including Odysseys, the Golden Bloon, Monkey Teams, and Boss Bloon Events.

Main gameplay
Gameplay in Bloons TD 6 is similar to previous games. The core gameplay is to stop enemy Bloons from reaching the exit(s) by making a defense consisting of various towers (called "Monkeys" in-game though some are clearly not monkeys). Popping Bloons will earn money, and can be used to buy more towers or upgrade existing towers. Each tower has a different role in the game. The game is played from a fixed top-down perspective, just like all other games of the Bloons TD series, but Bloons TD 6 uses 3D graphics, unlike any other of its previous games.

Bloons TD 6 introduces many new game mechanics, including Heroes, new Bloon types, 5th-tier upgrades, and a third upgrade path for each monkey. DDTs, which first appeared in Bloons Monkey City, also return in Bloons TD 6. The game also introduces three new Bloon types: The BAD (Big Airship of Doom) is the new strongest bloon in the game, and is immune to any form of slowdown, knockback, or instakill. Purple Bloons have been are a new counterpart to the Black and White Bloons, and are immune to fire, plasma, and energy weapons. The Fortified Bloon property is introduced alongside the returning Camo and Regrow properties; bloons with this property are stronger variations of their regular counterpart (the Fortified property will double the health of all bloons it is applied to except for Leads, which quadruples its health). Line of Sight is a new game mechanic that appears on certain maps, where certain types of obstacles can block certain towers from seeing over them.

Each game is divided into rounds. Every round normally consists of a pre-defined set of bloons of various densities and different bloon types, although Apopalypse Mode rounds are randomized on every new game. All rounds will gradually introduce more Bloon types and get harder the later the player progresses. Before starting a game, players are prompted to choose a mode - Easy, Medium, or Hard - and select a sub-mode. The variety of modes in Bloons TD 6 allows players to play the same map in many different ways, making the game more diverse than previous installments in the Bloons TD series. Upon completing a game, players will get a certain amount of Monkey Money based on the difficulty of the map chosen, and the mode chosen. After a map's first completion on a difficulty, the amount of Monkey Money rewarded upon completion is significantly reduced.

MOAB-Class bloons such as the MOAB, BFB, ZOMG and DDT return in BTD6, along with the new BAD bloon. These bloons only appear in rounds 40+, however, they all have a lot of health. MOABs require 200 hits to pop, BFBs require 700 hits to pop, ZOMGs require 4,000 hits to pop, DDTs require 400 hits to pop and BADs require 20,000 hits to pop, all gaining more health every round after Round 80. After defeating Round 100, players will receive an "Insta-Monkey" which has the chance of already having upgrades that can be placed for free in any mode except for C.H.I.M.P.S. and challenges with no powers.

Just like in BTD5, players can earn Monkey Money to unlock more stuff, including Powers, new Heroes, certain cosmetics, and unlock deeper Monkey Knowledge in conjunction with Monkey Knowledge Points. There is a new rare currency in the game called Trophies. Trophies can be used in the Trophy Store to unlock exclusive cosmetics not unlockable by Monkey Money.

Tutorial
Upon playing the game for the first time, Tutorial Monkey gives a tutorial on how to play the game. On the map Town Center, he declares the aim of the game: "Stop the Bloons from getting through!" The player is then instructed to place a 0-0-0 Dart Monkey inside the designated circle. After placing a second 0-0-0 Dart Monkey in another part of the track, the first round can be played. Tutorial Monkey then points out the Play button, which is used to begin the next round.

After beating the second round, he points out that popping Bloons earns the monkeys experience: "Popping Bloons earns your Monkeys experience!" He then instructs the player to tap on the Dart Monkey icon to unlock an upgrade. He tells the player that "each Monkey type has 5 upgrades in 3 paths," after which the player is free to choose one of the Dart Monkey's Tier 1 upgrades to unlock.

After unlocking an upgrade, Tutorial Monkey tells the player that he needs to apply the upgrade to the Dart Monkeys in play in order for them to be able to use it.

After completing Round 3, Quincy, one of the thirteen current heroes, arrives. Tutorial Monkey tells the player that Quincy is a Monkey Hero that upgrades himself throughout the course of the game.

After Round 4 is completed, the player levels up to Level 2, allowing the player to unlock a Primary Monkey. The choices for them are Boomerang Monkey, Tack Shooter, Bomb Shooter, Ice Monkey, and Glue Gunner. The same process occurs after Round 9 is completed, which is when the player levels up to Level 3, allowing the player to unlock another Primary Monkey.

After Round 10, the player wins the tutorial game and earns 100.

Monkeys
Bloons TD 6 currently features a roster of 22 monkeys (2 new monkeys and 20 returning from previous BTD games) and 13 heroes to help pop bloons. These monkeys are split into four classes: Primary, Military, Magic, and Support. The monkeys range from simple Dart Monkeys to the all-powerful Super Monkey, each one with its own unique attacks, abilities, and strengths. Monkey XP still exists, but this time around it functions a bit differently. Players can save up Monkey XP to unlock upgrades in any order they wish, but the amount of monkey XP required increases the farther down the upgrade path they travel. XP can also be saved, allowing players to go down the path the player wishes rather than unlocking them in order. Each monkey has its own set of XP so they cannot use Dart Monkey XP to buy upgrades for the Bomb Shooter, for example. Several towers have been renamed from BTD5, namely Boomerang Monkey (from Boomerang Thrower), Wizard Monkey (from Monkey Apprentice), Bomb Shooter (from Bomb Tower), Ice Monkey (from Ice Tower), Mortar Monkey (from Mortar Tower), Dartling Gunner (from Dartling Gun), and Engineer Monkey (from Monkey Engineer).

Each monkey offers 15 total upgrades which are split into 3 paths of 5 upgrades where a player can get two paths: 1 path to tier 5 and another path to tier 2. If someone upgrades one path then another, the path that wasn't chosen will be closed. Also, there can only be one fifth-tier upgrade for each path on screen at all times (except for the Crossbow Master upgrade, with the monkey knowledge activated known as "Master Double Cross", one can have 2 Crossbow Masters in a game instead of 1).

Heroes
As of version 26.0, BTD6 has 13 heroes which gain a fixed amount of experience each round and automatically level up to become stronger over time.

Hero skins
Heroes have unique skins, purchasable with Monkey Money, that change their appearance and voice lines. Hero skins do not have any impact on gameplay. 17 hero skins have been released as of version 28.0.

Bloon Types
Bloons TD 6 introduces various new bloons and their properties alongside many of the previous bloons from its prequel. In total, there are 22 different types of bloons, as shown below:

Normal Bloons


MOAB Class Bloons


Boss Bloons


Bloon properties
Bloons having properties inherit the same properties with their parents and share the same properties with their children. Their speed also remain unchanged.



Other Bloons


Maps
As of Version 30.0, there are 60 maps in Bloons TD 6. There are 19 beginner maps, 18 intermediate maps, 13 advanced maps, 10 expert maps, and one other map. The payout for completing a map depends on both the map's predetermined difficulty and the chosen game difficulty. After the first completion, the payout has a much smaller amount. (E.g. An Expert Map played on Hard difficulty will give more money than an Intermediate Map played on Easy)

Beginner:


 * Monkey Meadow: A grassy map. Similar to Monkey Lane from BTD5. This map contains no items blocking sight and no water, making it the simplest map in the game. In the 5.0 update, monkeys can be placed on the pumpkins at the top left and top right of the map despite the pumpkins being solid objects.
 * Tree Stump: A map around a tree stump. Bloons circle around the stump, then make a bigger circle before exiting. The tree stump will block the sight of towers, but towers on the stump have no restrictions. Similar to Park Path from BTD5. The axe in the log can be tapped to make it wiggle and the mushrooms can be tapped to make it glow and wiggle.
 * Town Center: A grassy map with a Bloons Monkey City vibe. Water lines the top left of the map, but is often too small and too far from the track to be useful unless using the Advanced Intel upgrade for the Monkey Sub. An additional option is to use Merchantmen as they generate money regardless of sight. There are crates near the building on the right that can be used for water towers before update 2.0.0. The buildings and the windmill are sight obstacles. This is the map featured in the tutorial of the game.
 * The Cabin: A dark and muddy map which is centered in the middle of a forest. This map features a relatively short winding path with a car that can be removed and a cabin. There's also a foggy atmosphere. Both the car and the house, along with all the trees, block placement and obscure line of sight.
 * Resort: A beach resort with a multi-rectangular path made of brick. Between the inside of the middle rectangle and the outside of the small square is a small swimming pool where water towers can be placed into. Taking in place on a beach resort, there are many items on the map. There are two red umbrellas to the right that can be opened or closed when clicked on. In the middle there are two lounge chairs and in between them a table that has a pink cocktail on it and a plate of bananas. To the right there's a pool in which water-based towers can be placed. All land-based towers can be placed anywhere except directly on the brown brick-layered bloon track, on the table, on where the bottom-left palm tree is, or on top of the umbrella stands. The umbrellas and the palm tree at the bottom left function as line of sight blockers so it's best not to place towers around them.
 * Skates: A map set on top of a frozen lake.  Bloons travel across the lake in a series of three loops.  The map features a large hole in the ice where water-based towers can be placed, as well as a group of cottages that can be removed to reveal a second hole in the ice for more water towers.
 * Lotus Island: An island in the middle of the sea, which has a few lotus plants and the remains of some sort of stone building. The Bloons travel around the perimeter of the island.
 * Candy Falls: A candy-filled map with a chocolate river flowing down the middle where water monkeys can be placed. The map is based on Willy Wonka's Chocolate Factory.
 * Winter Park: A snow-filled park area with a small fountain in the middle where water monkeys can be placed.
 * Carved: A track that resembles a Jack-O-Lantern.
 * Park Path: A clean, nice environmental, long and curvy track with water in a stream, returning from BTD 5. Sort of resembles a spiral.
 * Alpine Run: A snowy map based off of a ski lift.
 * Frozen Over: An icy themed map kind of resembling Ice Flow from BTD5. The map features many triangles with lots of room for water towers.
 * In the Loop: An autumn-themed map. Bloons follow a square that has loops on 3 of its corners. There is water in the upper right loop. The trees and tools on this map can block a monkey's line of sight.
 * Cubism: An abstract art map. Bloons go around the triangles and quadrilaterals. There is water in the lower right corner and in one of the triangles, allowing for water towers to be placed on this map. This map features two storm drains that do not affect gameplay.
 * Four Circles: A sprint track map. Bloons go around four circles. The top left and bottom right circles are each half water. This map uniquely features a timer near the bottom right that counts minutes and seconds. It blocks monkeys' lines of sight as well.
 * Hedge: A grassy garden map. Bloons go around the hedges. There is a statue in the middle of a Dart Monkey. Hedges along the track block monkeys' lines of sight, and cannot be removed. If the Dart Monkey statue is tapped, it rotates 90 degrees.
 * End of the Road: A desert road map. Bloons follow a horizontal road with two curves and then go back where they came from. There is water near the end of the road, allowing for water towers to be placed. The cacti on this map can also block monkeys' lines of sight although this doesn't practically affect gameplay.
 * Logs: A swamp-like map. The bloons follow a vertical checkerboard path and then follow a horizontal one, going under numerous logs. The middle square of the checkerboard-like pattern is water instead of land, allowing water towers to be used on this map. Monkeys cannot see through the logs on this map.

Intermediate:
 * Quiet Street: A map that features a mini-roundabout in a snowy neighborhood. Bloons take multiple entrances from the top and bottom of the map, on the left side. Small bloons stay on the sidewalk, while MOAB-class take the road. Hedges on the left block most towers from seeing the entrances. A tree blocks the center of the roundabout, but towers can be placed in the nearby snow at the foot of it. There is a frozen pond near each entrance which can be turned into usable water terrain for $500, and multiple parked cars on the edge of the mini-roundabout that can be moved for $250 each.
 * Bloonarius Prime: Set in a dank swamp, it appears to be the home of Bloonarius the Inflator. Bloons begin from the top-left entrance and naturally move towards its respective exit. On prime number rounds starting from Round 3, swamp holes will open, diverting bloons towards the shorter, less obvious lane.
 * Balance: A grassy area featuring a large circle in the middle, which has been split in half. Bloons travel across the green path, and two small pools of water are present in the bottom half.
 * Encrypted: A Halloween-themed map with multiple Bloon entrances. It takes place within a temple. The walls of the temple serve as line-of-sight obstructions. Outside the temple, there is a graveyard where towers of all kinds may be placed. Water-based towers may be placed on the waterlogged graves. Within the temple, there is a spot where towers of all kinds (except water-based ones) may be placed. Adjacent to the spot in the center, there are 4 pedestals covered by debris. The debris may be removed for $250 per pedestal. Each pedestal can only hold 2 towers that are within the specific tower type assigned to the individual pedestal. From left to right, top to bottom, the pedestals may house Magic, Support, Primary, and Military towers. Ninja Kiwi has stated that there is a secret hidden within the map; however, at the time of writing this the secret has yet to be found.
 * Bazaar: The second community-designed map added to the game, and takes place at a desert marketplace. Many line of sight obstacles such as the trees and central marketplaces appear on the map. Bloons come from alternating lanes from opposite sides. Odd rounds begin from the top-left, while even rounds begin from the bottom-right.
 * Adora's Temple: A map that takes place on a temple with several fountains, multiple entrances and exits for Bloons, and layered steps to place towers on.
 * Spring Spring: A spring-themed map that features a center island with water surrounding. Bloons travel on two paths, with both paths having the same entrance and exit. There are no sight blockers in a practical sense (rocks around the edge block sight, but not enough to matter).
 * KartsNDarts: A map that resembles a race track. The main track starts from the left, underneath the tunnel, around the second loop anticlockwise, around the first loop clockwise, above the tunnel and out through the right exit. There are two sets of hay bales and tires that lie in each circle, these can be removed for $500 each.
 * Moon Landing: A map that takes place on the moon. Bloons travel through a path that features three craters, which Bloons spin around in a spiral pattern before leaving. The rims of each crater rise high enough to block line-of-sight from most angles, making Mortar Monkeys ideal.
 * Haunted: A map that resembles the outside of a haunted house. Bloons come towards the house and come back to the entrance (resembling trick-or-treating). There are two trees next to the house that can be removed for $500 each.
 * Downstream: A map that takes place in a meadow, similar to Monkey Meadow. The bloons take two loops around the track. There is a large stream in the middle of the screen, hence the name. You cannot place towers in the middle of the loops until you clear the rock debris (each for $350). Added in 4.0 update.
 * Firing Range: A map that takes place in a firing range. The bloons move back and forth in the firing range itself and come down both sides to the exit. Towers cannot be placed in the sand of the firing range. There is a watchtower in the middle that blocks the vision of monkeys, but it can be removed for $1,000, along with a Ground Zero Bomber cinematic animation. Added in 2.0 update.
 * Cracked: A ruined land map. This map features a rock that can be removed for $1,000 but otherwise blocks a monkey's vision. Underneath the rock is a small body of water. Oddly, this map features a sign that can block towers from being placed on it but does not block the monkey's vision.
 * Streambed: A map that takes place in a dried-up streambed. There is a moderate-sized body of water near the bottom of the map. A fossilized skull in the middle of the map blocks line-of-sight, but can be removed.
 * Chutes: A temple map. Bloons come out starting on the left path, then alternating. There are two monkey statues in the middle, which you can remove for $350 each. Otherwise, they can block the sight of monkeys.
 * Rake: A cherry blossom/Japanese sand garden map. Bloons come out of two sides at once and leave in two places. This map contains a small body of water. There is also a statue that can be removed for $1,000, which will block the monkey's sight if not removed. Before the 4.0 update, it used to cost $350 to remove the statue. Oddly, the rake on the top left of the map does not block line of sight but does not count as viable land for placing towers.
 * Spice Islands: An island/archipelago map, consisting mostly of water. The palm trees can block a monkey's line of sight but can be removed for $1,000. This map was featured in a teaser to Bloons TD 6.

Advanced:


 * X Factor: A nature-themed map in the middle of a forest clearing, which has four paths which intersect in an X shape. Between rounds, the Bloons alternate which of the four paths they enter and exit from.
 * Mesa: A canyon map with two different pathways. Rocks can be removed for $500 each to place towers on the rock arches.
 * Geared: The first community-made map added to the game, it is a gear style map that monkeys spin around on a rotating gear that rotates every round. There are no obstacles on the map. Bloons go around the outer half of the gear.
 * Spillway: A toxic waste dump, filled with waste. Four walls block water towers from shooting in the middle, but each can be removed for $2000 per wall.
 * Cargo: A car filled lot of pavement with a ton of boats and water nearby to transfer cargo. After round 39, a new path opens up, which only MOAB-class bloons take, and two trucks that block vision can be removed for $500 each.
 * Pat's Pond: A swamp map with a large body of water in the center. Bloons travel on two paths, with the entrance of one being the exit of the other and vice versa. Two sets of trees and rocks can be removed for $500 each.
 * Peninsula: A rocky map that has water on three sides with few places to place towers. There are 3 rocks with debris on them, which can be cleaned of debris for $500 each. A large hill is also present that blocks sight. Towers can be placed on patches of grass.
 * High Finance: A city/construction map. Bloons will move first in an S-shape and then a U-shape around blocks of the construction area. A small bridge is present in the middle that allows water placement and early placement of towers similar to Cornfield. Each on the individual construction areas counts as sight blockers however they can be built up and towers may be placed on top to see over the other unbuilt areas. The cost to build each block ranges between $350 to $1,500. To build everything on this map it costs $12,550. Added in the 3.0 update.
 * Another Brick: A brick wall map. Bloons go around a wall, which counts as a sight blocker. The entire left side is off-limits for placing, but it is possible to remove each palette of bricks for $1,000 each to free up space for Banana Farms, Aces, Heli Pilots, Temples, Alchemists or anything that can bypass the line of sight. Small water puddles are present.
 * Off the Coast: A beach map. Bloons come from the water at the bottom to the beach and then go back to the water. This map features a wrecked ship in the water that blocks water towers from being placed on it, and cannot be removed. Land towers, however, can be placed on certain parts of the wreck, such as on the crow's nest and the bow.
 * Cornfield: A cornfield map. At the start, the only area where the player can place towers is a small square in the middle. The player may uncover more land by paying to remove the cornfields. The cost to remove a cornfield ranges from $350 to $1,500. It is possible to place towers within the dirt separating the cornfields if positioned correctly.
 * Underground: A cave-styled map. The bloons go around two rounded interlocking railroads. There are no objects that block the monkey's vision in a practical sense (rocks along the edges block vision, although this doesn't affect gameplay significantly.)
 * Sunken Columns

Expert:
 * Sanctuary: An ancient-style track where the Bloons travel along vines. Towers can be placed on platforms that move every round.
 * Ravine: Same aesthetics as Dark Castle. There are 2 entrances and 4 exits. There are many sight-blocking obstacles that cannot be removed. There is water, but water-based towers are boxed out of track access via the trees, bridges, and ravine walls. The camera is also tilted isometrically.
 * Flooded Valley: A map set at a dam. The track appears as though it is single-lane, but instead bloons come from both sides simultaneously and exit from opposite ends. The left-hand side is land that is heavily blocked by the extremely tall dam, while the right-hand side purely consists of water.
 * Infernal: A map set deep within a volcano. The track consists of two paths made of many small floating stones that interweave in the middle of the map; the entrances of these paths are on the left side of the screen, and the exits are on the right side. There are some small stone islands, two of which have water, on which you can place towers.
 * Bloody Puddles: A more difficult version of Muddy Puddles, featuring five paths instead of four to make it more difficult to deter the Bloons. There is also a broken-down jeep stuck in the mud, which can be removed for $1000. However, paying to remove it instead triggers a gag where the Chinook that shows up to remove the jeep breaks down and falls, taking up even more space. After this, the Chinook, jeep, and nearby stones can all be removed for a single purchase of $500.
 * Workshop: A map based in a factory setting. Many tables block vision, and the path is very short. After round 39, a new path opens up, which only MOAB-class bloons take. Two machines can be activated for free the first time you use them, with one making the main path longer and the other slowing bloons, and will deactivate after a certain time. However, reactivating them costs a steadily increasing price.
 * Quad: A grassy map with four entrances/exits for bloons. Four floral trusses blocking near each entrance/exit can be removed for $1500 each. A pond in the middle allows for the placement of water towers.
 * Dark Castle: A castle themed map kind of resembling the map Siege from BTD5. There are four entrances and one exit. Towers can be placed on top of the castle in a small place, but other places will block their sight. There are trees blocking sight of incoming bloons until 3/4 of the map, but these three trees can be removed for $1000.
 * Muddy Puddles: A muddy field map. Bloons come out of the four squiggling paths, alternating each round. Puddles are present between some of the paths allowing Buccaneers and Subs to be placed.
 * #Ouch: A city or road map. Bloons come out four ways and leave four ways, all at the same time. The water in the middle can be removed for $1,000, but cannot be removed if towers are placed in the water. This map is similar to the Extreme Map Main Street featured in BTD5, albeit with more accessible water and another set of paths. This is also very similar to Phase Crystal in Bloons Monkey City.

Other:
 * Blons: A grassy map with a pond in the lower right quarter. The map has one very short path in the top-left corner forming two sides of a square. According to calculations of hero-leveling rates, Blons is considered an Expert Map within the game. Only accessible in the Challenge Editor.

Game Modes
There are a total of 17 different game modes in BTD6, all of which are accessible in different categories of difficulty per map: Easy, Medium, and Hard. To unlock a specific game mode, the previous game mode must be unlocked, starting with the respective Standard Mode of a specific map. The Standard Mode option for all grades of difficulty is unlocked by default for all maps. As of the 19.0 update, beating a submode (a mode other than Standard) in an Odyssey will earn the player the corresponding medal and unlock the next submode in the path, if any, regardless of whether it was unlocked.

Easy:


 * Standard - On Easy bloons move a little slower, towers and upgrades cost 15% less than normal, and you have 200 lives.
 * Primary Monkeys Only - Only primary monkeys can be used (requires Standard to be completed)
 * Sandbox - Test towers and bloons in a safe environment, on Easy Difficulty settings (requires Standard to be completed)
 * Deflation - Start with a fixed sum of cash, but you can't earn anymore (requires Primary Only to be completed)

Medium:


 * Standard - On Medium everything is normal, and you have 150 lives.
 * Reverse - Bloons come from the opposite side of the track (requires Standard to be completed)
 * Military Monkeys Only - Only military monkeys can be used (requires Standard to be completed)
 * Apopalypse - Bloon waves progress without stopping (requires Military Only to be completed)
 * Sandbox - Test towers and bloons in a safe environment, on Medium Difficulty settings (requires Reverse to be completed)

Hard:


 * Standard - On Hard, bloons are faster, towers cost more, and you have 100 lives, starting at Round 3.
 * Sandbox - Test towers and bloons in a safe environment, on Hard Difficulty settings (requires Standard to be completed)
 * Alternate Bloons Rounds - Bloons have an altered RBE, making it more tricky (requires Standard to be completed)
 * Magic Monkeys Only - Only magic monkeys can be used (requires Standard to be completed)
 * Impoppable - Even costlier towers and upgrades, 100 rounds, and 1 life only, starting at Round 6 (requires Alternate Bloons Rounds to be completed)
 * Double HP MOABs - MOABs have 2x health (requires Magic Monkeys Only to be completed)
 * C.H.I.M.P.S. - Hard mode starting at Round 6 with special rules: No Continues, Hearts Lost, Income, Monkey Knowledge, Powers, and Selling (requires Impoppable to be completed)
 * Black CHIMPS medal if completed in one sitting (no saves)
 * Half Cash - Earn half cash from popping bloons, end of round bonuses, cash drops, Banana Farms, starting cash, and all other forms of income (requires Double HP MOABs to be completed)

Co-Op
Co-Op Mode has been first introduced to BTD6 in Version 11.0. Co-Op can be played with 2-4 players per game. Unlike BTD5, there are a number of maps where space is shared universally among all players, particularly on maps where placeable land is insufficient when divided. Just like in BTD5, players can exchange income with each other along with requesting for income.

The player may play in a Quick Match, which allows them to play publicly with any player across the world, or they can create private matches via Create Match and Play Match (right term?).

Challenge Editor
Challenge Editor is used to make various challenges in BTD6. In Challenge Editor, players can set the map, difficulty, starting cash, lives, rounds, and other special parameters to increase the overall complexity of the challenge. For instance, the health and speed of regular bloons and MOAB-class can be increased or decreased, certain towers and/or upgrades may be restricted, certain quantities of towers may also be restricted, and certain CHIMPS rules (i.e. in this case, Continues, Hearts Lost, Monkey Knowledge, Powers, Selling, but not Income) may be implemented too. Additionally, the player may set all regular bloons to become Regrowth and/or Camo.

Players may share their challenge code of their challenge once it is completed without the use of Powers. Players may also send their challenge to Ninja Kiwi once they have successfully completed the challenge, along with indicating their identified difficulty rating (Easy, Medium, Hard, Friday Stinger).

In Version 22.0, a content browser was added in-game along with the ability to like and favorite challenges. Regrow Rate was also added as a new slider option.

Odyssey Creator
Odyssey Creator is very similar to the Challenge Editor, where players can create their own entire odyssey with a length of 3 maps (easy), 4 maps (medium), or 5 maps (hard). Each map can have its very own separate Bloon modifiers and certain CHIMPS rules and their own starting cash and rounds. On top of this, the player can also adjust the starting lives and max seats and max towers for both Towers and Powers. It is also possible to toggle on or off an Extreme Mode Odyssey.

Content Browser
The Content Browser, previously known as the Challenge Browser from Version 22.0 to Version 25.0, is where players can share their custom Challenges and Odysseys online to everyone. The player can search for a specific challenge name or challenge code, along with several filters including time uploaded and including creations made in older versions. There's also a slider for maximum rounds and minimum rounds in a challenge. There are separate [...]

Events
Four distinct types of events are available: Collection Events (including seasonal and non-seasonal variants), Race Events, Odyssey Mode, and Boss Bloon Events. Completing them will earn special unique bonuses that can improve on player gameplay in the game. Trophies are a unique currency that is earned by completing Race Events or a full Odyssey on Odyssey Mode. Collection Events earn free Insta-Monkeys based on a lootbox-esque system without paying in-app purchases.

Collection Event
Collection Events are events where special lootbox currency can be earned to receive free Instamonkey boxes with randomized Instas. Tiers of Instamonkeys and quantity of earned Instamonkeys increases with higher-tier chests. Collection Events are usually seasoned, normally appearing on special holidays, but are sometimes seasonless with its default theme as Indiana Jones. These events typically last between 7 to 14 days.

Odyssey Mode
Odysseys are special multi-game modes where the player progresses through a journey of 3-5 different maps with special rules set in each island, and lives spread across throughout the adventure. [more info later...]

Race Event
Race Events are weekly events where players can play a pre-defined challenge and attempt to speedrun as fast as possible. The key difference in Race Events is the option to speed up rounds by sending in the next rounds. If the player completes the entire challenge while still surviving in a single attempt, they will be added to the Race Leaderboard. If the player loses, however, they will have a chance to participate in the Race again with either a 100 fee or waiting every 3 hours until a free race attempt refreshes. Race Events usually last for 5 days, from Friday 8:00pm NZST to Tuesday 3:30pm NZST.

The winners of the race are announced several hours after the Race Event ends. Winners of the race receives prestigious badges plus valuable rewards, including Trophies. The grand winner and runners-up will receive much more valuable rewards, including exclusive badges. Badges do not affect gameplay and are mostly for bragging rights.

Boss Bloon Events
Boss Bloon Events are events involving fights against Boss Bloons. Boss Bloons begin starting on Round 40, and they must be beaten within 20 rounds per tier in order to win each stage. Boss Bloons possess various unique properties, contain extreme amounts of health, and are even more relentless than BADs. Each Boss has 5 tiers before they will be finally defeated, and must be beaten before Round 140. Each of the Boss Bloons have Elite variants with much more difficult stats, but requires the normal variant to be beaten first before encountering its Elite variant. There are also Ranked Bosses which are essentially the same event but the player is timed and placed on a global leaderboard for even more prizes.

Seasonal Offers

 * may need more expansion...

The game currently celebrates the following:
 * Easter
 * May the Fourth
 * American Independence
 * Halloween
 * Christmas

Special offers in each of the aforementioned seasons may be given during these periods.

Trophy Store
Trophy Store is a store where players can redeem exclusive new cosmetic content with Trophies. The Trophy Store was added on Version 19.0, providing a use for the Trophies currency. All Trophy Store items can be activated or used in C.H.I.M.P.S. mode.

Trophy Store items have always been added on every major update starting from Version 19.0. Many updates also add limited-time Trophy Store items too.

Achievements
Optional achievements can be earned for extra rewards and pride for the player. Most of these extra rewards involve either free Monkey Money, Powers, Instamonkeys, or Monkey Knowledge Points. The "Achievements" button can be tapped to find a list of possible achievements.

Some achievements are secret achievements, and can only be earned through very special means.

Profile
Profiles are used to display the player's progress in the game, with a special menu added since Version 18.0. It is publicly showable for any feature involving use of the internet. Statistics can be displayed onto the profiles, up to 7 statistics.

History
Bloons TD 6 was announced on March 28, 2017 on PRLog for the iTunes App Store, Google Play Store, and Amazon App Store and released on June 13, 2018. [https://ninjakiwi.com/blog/news/173252-what-s-up-at-ninja-kiwi-27-october-2017 What's Up At Ninja Kiwi? - 27 October, 2017] The game, like its predecessors, revolves around popping Bloons using monkey towers. Unlike the previous games, however, Bloons TD 6 utilizes 3D graphics to enhance visual gameplay. The game also utilizes a new feature called Line of Sight, a feature where certain obstacles can block the monkey's line of sight, which makes tower placement significantly more important. Certain vision-blocking objects can be removed for a fee, which will free up space for tower placement and sometimes can add other gameplay effects such as revealing hidden water.

On December 17th, 2018, BTD6 Steam for Windows was released worldwide, initially released with Version 7.0. BTD6 Steam for Macintosh was released worldwide much later on, starting from 12th March 2020 with the release of Version 16.2.

On January 25th, 2019, BTD6 Steam for Windows got 10 Trading Cards in the Steam Community Market.

On June 4th, 2021, the Windows Store version of Bloons TD 6 was released, with almost identical gameplay and features compared to the Steam version for Windows.

Timeline of Published Information
Bloons TD 6 underwent many changes ever since it was officially announced on 27th March 2017. Although it was delayed until June 2018, there were many teasers for the game along the way, including introduction to new towers and new Heroes.

Version History
Bloons TD 6 regularly has a new major update every 40-50 days on average. All major updates have consisted of major balance changes across many aspects of the game to refresh the game with fair and interesting gameplay across each update, often to challenge dominating metas in the game or to improve aspects of the game that are quite underused.

Balance changes
There were various balance changes occurring on each update, adjusting a variety of different towers towards a relatively equal power for their own unique special fields of expertise.

For the most part, many of the balance changes in the game each update were designed to reduce the overpoweredness of certain towers and/or their combos, while at the same time allowing certain other towers and their upgrades to become more usable choices in certain scenarios. For certain upgrades, crosspathing interactions have also been adjusted in certain updates to balance out the overall power for the alternate crosspathing ends for different scenarios, such for the Crossbow Master, where Path 1 crosspaths granted even more pierce bonuses in exchange for Path 2's plain bonus attack speed.

Bloons TD 6+
Bloons TD 6+ is an Apple Arcade game version of the original Bloons TD 6, exclusive to iOS devices with Apple Arcade. It was confirmed on 2nd February 2022. It was released on 11th February 2022.

Trivia

 * Ninja Kiwi said they would officially release Bloons Tower Defense 6 on 14th June 2018, but it was instead released a day early, on 13th June 2018. This is probably because the mentioned date was the release date in New Zealand time, which is very close to the International Dateline.
 * As of 6/15/18, Bloons TD 6 was the number one paid app on the Appstore and Google Play Store. Similarly, Bloons TD 5 previously made it to the top few games on the Appstore and Google Play Store, and still holds a high rank in both stores.
 * On the main menu screen, the left palm tree, left house, windmill, town hall, the right side of the shore, and the middle statue can be tapped. Upon being tapped, a different monkey reacts depending on which item was tapped.
 * Tapping the palm tree will cause a Boomerang Monkey to pop up and throw a boomerang.
 * During the 5.0 update and later 13.0 update, the Boomerang Monkey will appear to be costumed like a zombie, having pale white fur, blue skin, and black eyes with white pupils.
 * During the 7.0 update, the Boomerang Monkey will appear to be costumed like an elf.
 * During the 10.0 update and later 24.0 update, the Boomerang Monkey will appear to be costumed like an Easter bunny and will throw a carrot instead of a boomerang.
 * Tapping the left hut will cause two Bomb Shooters to appear and fire bombs at each other.
 * During the 5.0 update and later 13.0 update, the Bomb Shooters will fire a small pumpkin at each other instead.
 * During the 7.0 update, the Bomb Shooters will fire a small peppermint candy.
 * During the 10.0 update and later 24.0 update, the Bomb Shooters will fire an orange gumball.
 * Tapping the town hall will cause a Ninja Monkey to jump up and vanish in a puff of smoke.
 * During the 5.0 update and later 13.0 update, the Ninja Monkey will appear to be costumed like a mummy.
 * During the 7.0 update, the Ninja Monkey will appear to be costumed like an elf.
 * During the 10.0 update and later 24.0 update, the Ninja Monkey will appear to be costumed like an Easter bunny.
 * Tapping the windmill will cause a Monkey Ace to fly across the screen and the windmill to rotate.
 * During the 5.0 update and later 13.0 update, the Monkey Ace will appear to be costumed like a vampire and the plane will resemble a giant bat.
 * During the 7.0 update, the Monkey Ace will be replaced by Santa Monkey in his sleigh.
 * During the 10.0 update and later 24.0 update, the Monkey Ace will appear to be costumed like a chicken. The plane also appears to take on a chicken-like appearance.
 * During the 11.0 update, the Monkey Ace will leave behind a trail of Red, White, and Blue.
 * Tapping the statue will cause a Dart Monkey to peek out from behind.
 * During the 5.0 update and later 13.0 update, the Dart Monkey will appear to be costumed like Frankenstein's Monster.
 * During the 7.0 update, the Dart Monkey will appear to be dressed like an elf.
 * During the 10.0 update and later 24.0 update, the Dart Monkey will appear to be costumed like an Easter bunny.
 * Tapping the right side of the shore will cause a Monkey Sub to appear.
 * During the 5.0 update and later 13.0 update, the Monkey Sub will be replaced with a Pirate Lord instead.
 * During the 7.0 update, the Monkey Sub will appear to be dressed like an elf.
 * During the 10.0 update and later 24.0 update, the Monkey Sub will appear to be costumed like an Easter bunny.
 * During the 5.0 update and later 13.0 update, you can tap/click the pumpkins on the left and right sides of the screen and the eyes/mouth of the pumpkins will light up.
 * The Bloonchipper is the only tower from Bloons TD 5 that is not returning to Bloons TD 6. As of now the Mortar Monkey, Monkey Engineer, and the Dartling Gunner are already in the game.
 * Towers in BTD6 have a total of 15 upgrades to choose from (3 paths of 5). which is almost twice as many upgrades per tower BTD5 had to offer (8 upgrades among 2 paths of 4).
 * However, each monkey can only have a maximum of 7 upgrades purchased, up only 1 from the 6 upgrades in BTD5. This is only for the 1 tier-5 tower on screen; all other towers can purchase only 6 upgrades
 * This is possibly to prevent monkeys from being too powerful and the game being too easy, as crossing all 3 upgrade paths can result in drastically improved damage output.
 * The town hall in the main menu shows the time of the player's device.
 * The tower stacking glitch that BTD5 Players used to exploit using Support Chinook no longer works in BTD6 even since the initial release.
 * BTD6 Steam for Mac came out over a year before BTD6 Steam for Windows, even though Bloons Adventure Time TD Steam supported Macintosh ever since the Steam version's original release date.
 * BTD6 was free to purchase for the first time on 22nd/23rd May 2019.
 * On September 11th/12th 2019, one day after the BTD6 community discovered that display text could be attributed with textual code (e.g.  or  ), Ninja Kiwi announced that they will ban players who use such exploited coding onto their display username if detected on public Co-Op matches or on public leaderboards (i.e. Race Events, as there aren't any other public leaderboards of that date). This post can be featured here. This ban announcement did not affect Custom Challenges.
 * Up to 14 characters may be used for the display username.
 * On mobile devices, attempting to play music from an external app such as the built-in iOS's Music app while the game music plays will cause both the music from the app and the game to play simultaneously. However, starting the music before the BTD6 app loads will cause the music to override both the music and the sound effects.
 * As of Version 21.0, the name of the game over message was changed from "Defeat" to "Game Over", but only for losing after initially winning.
 * On the date 21st January 2021 on 9:58am NZDT, 6,073,283,850,717 Monkey Money was earned in total, and 80,302,074 Insta Monkeys collected, and 3,138,290 players have been defeated by Round 90 (assuming normal games, that is).
 * The name "Bloons Tower Defense 6" has not been seen in any mention of this game by Ninja Kiwi, with exception of the official Bloons TD 6 website, and has always been consistently written as "Bloons TD 6".
 * There are currently no maps with the letter "J" since initial release, updated as of Version 25.0.
 * 1000 days since the initial release of BTD6 is March 8th 2021.
 * According to steamcharts.com, BTD6 Steam's all-time peak of Steam players was on March 15th 2021. Link.
 * If a player's device is old, the device has low storage, or the game is laggy, map animations will stop.
 * This is the first Bloons TD game that does not have a Flash counterpart.
 * Bloons TD 6 is the first and only Ninja Kiwi game to feature both the modern 2D Ninja Kiwi logo and the "shining blade" production logo.

NK blogs

 * On Ninja Kiwi's October 8th 2021 blog, they made an official response about comments about BTD6 being so-called "pay-to-win". In short, they assertively say that the game must be bought to play but also state that game mechanic balance in Bloons TD 6 does not rely on microtransactions at all.
 * According to Ninja Kiwi's October 8th 2021 blog, they stated that the game's voice actors are hired from a voiceover agency called bigmouthvoices.com.
 * Ninja Kiwi stated on their October 22nd 2021 blog that the Version 28.0 update took a very long time to complete due to a combination of working at home during viral lockdowns, adding in ranked bosses, and upgrading the game engine.
 * According to Ninja Kiwi's October 29th 2021 blog, monkeys take breaks from battle every once in a while.
 * According to Ninja Kiwi's 5th November 2021 blog, two questions were answered regarding future development of BTD6.
 * The iMessage BTD6 extension is not planned to be updated, as of this date. The iMessage BTD6 extension has not been updated since its initiation when the game was first released.
 * On the same blog, a Nintendo Switch version of BTD6 is not planned, given the amount of workload currently at Ninja Kiwi as of the time posted.
 * According to Ninja Kiwi's 18th February 2022 blog, as implied by a specific question and its context to refer to BTD6, app downloads for new updates are large because of the need to update the majority of app assets in the game.