Bloons TD 4

"BTD4 features improved graphics, loads of new and original tower types and tons of upgrades for each tower type. Heaps of tracks, save games, career mode, sandbox mode and apopalypse mode. Bloons Tower Defense 4 will give you almost unlimited replay value. Also included is optional MochiCoins premium content featuring lots of extra tracks and special booster upgrades like double boomerangs, exploding darts, and double cash!"

- Official Description

Bloons Tower Defense 4 is the fourth installment of the popular Bloons Tower Defense series, released on October 26, 2009. The game has many new features, including but not limited to improved graphics, new towers and new modes. This game also has an expansion, with new maps and Specialties, which affect the cost of certain towers.

Gameplay

 * Bloons TD 4's gameplay is extremely similar to the previous three games. As said above, Bloons Tower Defense 4 has many new features. These include:
 * Refined graphics. Bloons Tower Defense 4's graphics are heavily improved from Bloons Tower Defense 3.
 * New maps. The game has 9 free maps (3 beginner maps, 3 intermediate maps, 2 advanced maps and 1 expert map). There are also 8 Premium maps, purchasable with varying amount of NK Coins.
 * There are 6 new towers: the Glue Gunner, Monkey Ace, Mortar Tower, Monkey Apprentice, Banana Farm, and Monkey Buccaneer.
 * New and improved upgrades for towers.
 * Ranking system, based on the number of bloons the player has popped.
 * Brand new Bloon types, also introducing the Camo Bloon.
 * Two new modes, Apopalypse Mode and Sandbox Mode.

"Bloons will come non-stop until you run out of lives."

- Official description of Apopalypse

In Apopalypse Mode, the gameplay is mostly the same, except for one key difference: there are no breaks between rounds, with spawned Bloons becoming tougher over time. The costs of tower and upgrades are equivalent to Medium Difficulty.

"In Sandbox Mode, you have unlimited money and lives and you can choose which Bloons come and when."

- Official Description

In Sandbox Mode, the player starts with $1,000,000 and 100,000 lives. The player can spawn any type of Bloons at any time. The prices are also in Medium.

Easy Difficulty
On Easy mode, things are cheaper than usual (85% of medium) and players start with 200 lives. There are 50 rounds to pass.

Medium Difficulty
On Medium mode, things are regularly priced (see above) and players start with 150 lives. There are 60 rounds to pass.

Hard Difficulty
On hard mode, things are more expensive (108% of medium) and players start with 100 lives. There are 75 rounds to pass.

Sandbox Mode
In sandbox mode, players have 1,000,000 money and 100,000 lives. Things cost as much as in Medium mode (see above). In Sandbox mode, players can choose what Bloons to release and at what times. For example, players can click a button to release 20 Red Bloons, 5 Ceramic Bloons, or 1 MOAB. Players can try releasing other bloons as well.

(Note: This mode is unlocked once rank 26 is achieved. Lives and Coins are NOT unlimited.)

Apopalypse
In Apopalypse mode, players have as much money and lives as in Medium, and things cost as much as in Medium (see above). Once the player click the 'Start Round' button, bloons will never stop coming and continue to get stronger and stronger. Even though bloons never stop coming, rounds still exist — they are just started automatically. Therefore, Banana Farms still grant players bonus money at the end of each round. If no road spikes/monkey glue were used completely, they will still exist.

(Note: This mode is unlocked once rank 31 is achieved.)

Challenges
Bloons Tower Defense 4 introduced a new gameplay called Challenges. These challenges include limited towers and a certain track. Every track allows Road items. Only 4 have been made:
 * Challenge 1: Pass Ocean Road on Medium with only using Dart Monkeys and Super Monkeys!
 * Challenge 2: Pass Sweet Tooth on Easy using only Dartling Guns and Spike Factories!
 * Challenge 3: Defeat a wave a 50 M.O.A.B.s with $50,000. (Pool Table)
 * Challenge 4: Pass Ant Hill on Hard without losing a single life!

Premium Upgrades
Bloons Tower Defense 4 features Premium Upgrades for various new tracks and new abilities for towers.

Upgrade/Cost (in NK Coins)

Tracks

 * Daisy Chain
 * Cost: 15
 * Space Age Track
 * Cost: 15
 * Clifftop Track
 * Cost: 15
 * Grasslands Track
 * Cost: 15
 * Inter-Dimensional Track
 * Cost: 15
 * High-Tech Track
 * Cost: 15
 * Railway Track
 * Cost: 15
 * Track Pack
 * Cost: 75
 * Effect: Buys every premium track. Saves 30.

Upgrades

 * Cash Injection
 * Cost: 3
 * Effect: One-time cash boost of $10,000. Only works for current game.
 * More Lives
 * Cost: 3
 * Effect: One-time boost of 200 lives. Only works for current game.
 * Frag Bombs
 * Cost: Free
 * Effect: Bomb Towers bomb's explosions release fragments that fly and pop even more bloons.
 * Double Ranga
 * Cost: 15
 * Effect: Boomerang Towers throw 2 boomerangs and can pop up to twice the number of Bloons they normally pop.
 * Exploding Darts
 * Cost: 7
 * Effect: Dart Monkeys' darts now explode at the end of their pop, letting them pop Lead bloons.
 * Crystal Ball
 * Cost: 10
 * Effect: When activated, it greatly increases Monkey Apprentices' attack range and allows detection of Camo Bloons.
 * Dreadnaught
 * Cost: 12
 * Effect: When activated, instead of darts, Monkey Buccaneers will now fire flaming cannon balls capable of popping frozen and lead Bloons.
 * Digital Amplification
 * Cost: 15
 * Effect: When activated, Monkey Beacon towers have a massive, enhanced radius.
 * Monkey Tycoon
 * Cost: 12
 * Effect: When activated, selling towers results in a full refund rather than the normal 80%.
 * Healthy Bananas
 * Cost: 15
 * Effect: When activated, Banana Farm towers grant +1 life per upgrade per round, including the farm itself.
 * Double Cash
 * Cost: 24
 * Effect: While selecting the mode, you may turn Double Cash on or off. When turned on, each popped Bloons grants $2 money instead of $1; double cash is also given when starting a game.
 * Buy Rank 31
 * Cost: 12
 * Effect: Instantly turns you into rank 31, unlocking all modes and final tower upgrades, except Dartling Gun and Spike Factory's final upgrades.
 * All Premium Upgrades
 * Cost: 100
 * Effect: Buys every premium upgrade. Saves 24.

Patched

 * The hot keys allow use of the towers, even if not unlocked.
 * Players can no longer activate Premium Upgrades without even paying NK Coins (This was done by clicking the edge of an upgrade button).

Not Yet Patched

 * Using hotkey abuse, players can place anything anywhere.
 * When the Boomerang thrower throws it's boomerang, his boomerang sometimes won't return to the tower but will vanish at about two thirds of the way around.
 * If players click on a tower and then right click on the road, and get rid of the menu thing that comes up, the player can place the tower on the road.
 * When there are many bloons on the screen, and when the Bomb Tower shoots its bomb/missile/MOAB Mauler, the player doesn't see it explode even if it hits a bloon. Same with the Mortar Tower and the Fireball.
 * On old computers, in the early levels, the game may freeze when you start a round, and then the round will be finished without a single bloon ever appearing on screen. This can complete the MOAB Madness challenge without placing towers.
 * Occasionally, the Missile Launcher will fire two missiles at once. This, however, is rare.
 * In later rounds, or on laggy computers, there will occasionally be a big black/white patch in the middle of the map. This also happens when too many road items are on the screen at one time.
 * With a tower or road item selected, if players RIGHT-click somewhere the player could normally place it, then LEFT-click anywhere on the map, players can place any tower or road item anywhere on the map.
 * If you upgrade a tower and then switch to another tower of the same kind before the upgrade finishes scrolling, then you can skip all the previous upgrades and the tower will act like that upgrade but without the previous ones.

Note: All of these bugs are visable in known bugs.

Rounds

 * 50 on Easy
 * 60 on Medium
 * 75 on Hard
 * 250 on Freeplay
 * Infinite on Apopalypse

Trivia

 * The actual last round is round 250 because there are no rounds programmed after.
 * Round 250 has 999 B.F.Bs, and it is almost impossible to reach that level without cheats.
 * Similarly to BTD5, bloons gain speed at higher rounds.
 * In BTD4 and all subsequent Bloons TD games, players receive less cash for popping bloons when in later rounds. They only get 50% of the normal cash for rounds 52-61 and 20% for rounds 62+.
 * The first challenge only lets players use Dart Monkeys and Super Monkeys, and it is very unlikely for players to have a Super Monkey with Plasma vision before Round 28. The Premium Upgrade, Exploding Darts allows you to pop Lead Bloons without using Pineapples.
 * In the third challenge players can still place a Dart Monkey by using the hotkey D.
 * BTD4 is the first and only game to have Camo Bloons as a seperate Bloon, rather than a property.
 * The camo bloon debuts in BTD4 but is its own bloon. In other games, the camo property can be applied to all bloons.
 * In the artwork for Bloons TD 4, as shown at the top of the page, and in the Ninja Kiwi link to the game the name "Bloons Tower Defense 4" is shown, but in-game and in Ninja Kiwi Archive it is "Bloons TD 4".
 * All towers in BTD4 have unique prices. This is not the case in later versions of the Bloons TD games.