Bloons TD 6 has been in development for a long time. Below is a list of information leading to its overall development.
Timeline of Events before initial releaseEdit
23 February 2010Edit
Ninja Kiwi registers the btd6.com domain via GoDaddy.
29 March 2017Edit
Ninja Kiwi publishes the first Bloons TD 6 announcement on PRLog, which states the initial goal of a 2017 release date, and features the first image of the Bloons TD 6 logo. 
AUCKLAND, New Zealand - March 29, 2017 - PRLog -- Ninja Kiwi Limited, an industry leading independent mobile games developer and publisher, confirmed today that it was hard at work on Bloons® TD 6 for the iTunes App Store, Google Play Store, and Amazon App Store. The team has not announced a launch date, as the immense scale and strategic depth of the game require an extensive balance and test period, but their goal is to release the game in 2017.
The game's precursor, Bloons TD 5, has been an app store phenomenon since its release in November 2012, remaining in the top 25 ranks of US app store paid charts throughout its life and recently returning to the #1 position on the US Google Play top overall paid apps and #3 US iTunes top overall paid apps. Attracting an impressive 9.3 million downloads as a paid mobile game, Bloons TD 5 has maintained a consistent 4.5 out of 5 star quality rating across the nearly 50 major content updates released to date.
Bloons TD 6 will maintain the series' captivating balance of family friendly visual style and challenging, skill based strategic play, but Ninja Kiwi is not currently releasing any information about new towers, new abilities, or new game modes. Consistent with the previous improvements from game to game, the company has said that their intention is to knock it out of the park, as Bloons TD 6 is designed to be more awesome in every way than its top selling predecessor.
27 October 2017Edit
A post on the Ninja Kiwi blog states that the release of Bloons TD6 was delayed to 2018, citing the want to avoid a "rushed game". The post includes an image of a Dart Monkey.
|What's Up At Ninja Kiwi? - 27 October, 2017|
We are hard at work on a BTD Battles mobile update, we're looking into what development time/resources we can swing towards SAS4 mobile/Steam (no ETA) and Bloons TD 6 is looking to be feature complete before the offices close down in December. With that we have some sad but encouraging news: BTD6 will be released next year. Putting the game together in a stable, fun and freakishly awesome package is our main priority. BTD5 is a lot to live up to and we don't want to let you or ourselves down with a rushed game. We will start releasing information and media about BTD6 to show it off a little, but it's ready when it's ready and here's a cheeky Dart Monkey modelling a dart to prove it.
23 November 2017Edit
HayleyBelleNK, an administrator of the Ninja Kiwi Forums, makes a post reiterating the delay to 2018. It features the silhouette of Quincy.
|Bloons TD 6 Update|
We thought it was time for an update on Bloons TD 6. In short we're now looking at a 2018 release. We can't say when but we do know we have a fair way to go before delivering the quality bar that our loyal (and patient) fans deserve.
BTW, Quincy says 'Hi.'
15 April 2018EditThe Bloons TD 6 Facebook account publishes an image of a corkboard, which depicts information concerning the Alchemist Monkey.
16 April 2018EditThe Bloons TD 6 Facebook account updates their cover photo to a new image of the Bloons TD 6 logo, and updates their profile picture to an image depicting a group of bloons, where notably a new purple bloon with a blue outline appears.
Aside from the purple bloon mentioned eariler, there is really not much to see.
19 April 2018EditThe Bloons TD 6 Facebook account publishes an image of a file, which depicts information concerning a monkey appearing to control the weather and plants, hinting at Obyn Greenfoot and/or the druid monkey.
Solving the substitution cipher yields the following potential results (highlight text to reveal).
Note at the top: A Guardian of te Forest and a Warrior of Nature
Enemy of Bloons
Paper sheet: Creates a blast of torns for each attack.
Upgrades can call forth ██████ of the ██████ storm or ████.
Photo note: Spirit Forest
24 April 2018EditThe Bloons TD 6 Facebook account publishes a collage of surveillance photos primarily depicting Quincy.
Aside from the obivous Quincy "screenshots", we can see the following:
A tape that says "HERO (A)".
Numbers at the top, which which can be converted to text: "son of quincy"
1 May 2018Edit
The Bloons TD 6 Facebook account publishes greyscale images of gameplay, the 3D model and texture of the Ice Monkey in Photoshop, and a photo of Unity 3D.
There are some towers on the gameplay image. These towers are:
The track appears to be an altered version of Monkey Lane.
9 May 2018EditThere are images of Gwendolin on the track. These images are presented as "footage" in the same manner as previous trailers.
One of the tracks appears to be the same as the track seen the Archer Monkey teasers.
16 May 2018Edit
A teaser roundup has been published on Ninja Kiwi's YouTube channel, showing everything they have published so far. In addition, the teaser has also been promoted via the Bloons TD Battles Mobile news menu. The teaser can be seen right here.
21 May 2018EditThe Bloons TD6 Facebook group has posted an image which showcases a brief bio of the hero Striker Jones, which includes details about his abilities and attacks as well as a few pictures of him on various tracks.
The bio features two pictures of what appear to be Striker Jones's artwork. The grayscaled picture depicts him carrying a rocket launcher, while the more polished, colorized picture shows him with a bazooka; it could be that his design has been changed during development, or an upgraded version.
As for Jones's bio, it is said that he's knowledgeable in long range combat and uses his skills to increase the power of explosives. This implies that his main function may be to increase the popping power of any tower that uses explosives. Additionally, the bio says he has two Activated Abilities, the Concussive Shell and Artillery Command.
25 May 2018Edit
A short gameplay demo is released, showing the new 3D models for the Sniper Monkey, Dart Monkey, and Monkey Sub. There also appears to be a new feature of landscape obstructions. There are various tracks shown, but most of them are just variations of BTD5 tracks. One of the tracks was previously shown in the Quincy teaser. The tracks in this teaser were revealed to be Hedge, Spice Islands, and Streambed, respectively.
This teaser is the first teaser to display the interface of the actual game.
Based on the blurred tower menu, it appears that Boomerang Thrower, Bomb Tower, Tack Shooter, and Ice Tower will almost certainly make reappearance in the game. Several other unknown towers also appear in the towers menu.
30 May 2018Edit
Bloons Tower Defense 6 is released on Google Play. However, it cannot be played until June 14.
On the App Store, the app is available for pre-ordering at the cost of $4.99 USD. In addition, the Facebook pages in Bloons TD Battles and Ninja Kiwi have promoted BTD6's post about the pre-releases. Based on the initial App Store release, it is expected to be fully released on June, 14 2018.
In addition, the official website is open.
|App Store description on first day of release|
Smash Hit Tower Defense Game 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!
ALL NEW 3D BLOONS TD
EPIC MONKEY TOWER UPGRADES
DEEP MONKEY KNOWLEDGE SYSTEM
And there's heaps more! We packed as much content and polish into this game as possible, and we'll continue to add new features, content, and challenges in regular updates. We truly respect your time and support, and we hope Bloons TD 6 will be the best strategy game you've ever played. If it's not, please contact us at email@example.com and tell us what we can do better! Now those bloons aren't going to pop themselves... sharpen your darts and go play Bloons TD 6!
Best experienced on iPhone 7 or above, or on iPad mini 4 or above
Bloons TD 6 contains in-game items can be purchased with real money. You can disable in-app purchases in your device's settings, or reach us at firstname.lastname@example.org for help. Your purchases fund our development updates and new games, and we sincerely appreciate every vote of confidence you give us with your purchases.
Ninja Kiwi Community:
We love hearing from our players, so please get in touch with any feedback, positive or negative, at email@example.com. If it's stuff you want the whole community to see and talk about, then join us on Facebook, Twitter, and Instagram:
The App Store description has confirmed a wide number of aspects of the game, thanks to how it has allowed pre-releases.
Many bloon types have been confirmed. Every Bloon type in BTD5 plus DDTs have been confirmed. It is also shown that many of the BTD5 towers will make a return in the new game.
Along these is special Tier-5 towers where only one tower may be upgraded to per game. In addition, there are now three upgrade paths per tower.
7 June 2018Edit
Ninja Kiwi posted a video showcasing the abilities of the Alchemist Monkey, one of the two new towers making their debut in BTD6. https://t.co/gOlRXqSyNS
Info on the list of confirmed towers is also revealed in the Ninja Kiwi Discord.
(Spiro 💉🎈 is Rohan)
AlextheTroller - Today at 8:03 PM
are banana farms gonna be annoying to collect like in btd5?
only if you want them to be but yes they are gonna be
K1d_5h31d0n - Today at 8:06 PM
What will come of Mortars, Dartlings, Engineers, and Chippers? I imagine they'd be added in updates.
Chipper is gone for good but the others are unknown
What will become of the Dartling/Mortar/Engineer?
They aren't finished, but they've been worked on.
Will probably be updated in at some point
but, wait and see :shrug:
This confirms that on initial release, every tower from BTD5, excluding the Mortar Monkey, Dartling Gun, Monkey Engineer, and Bloonchipper will be returning. The Mortar Monkey, Dartling Gun, and Monkey Engineer are likely to return in updates to the game, but the Bloonchipper will not see a return. Additionally, the Druid and Alchemist will be added as new towers.
9 June 2018Edit
Ninja Kiwi releases copies of the game to notable YouTubers to showcase before the official release. However, they are not allowed to show the fifth-tier upgrades until June 12th, when they would be allowed to showcase one fifth-tier upgrade per day(source?). In addition, in the Ninja Kiwi Forums, the BTD6 subforum has opened, further confirming BTD6's full release coming soon.
13 June 2018Edit
Bloons Tower Defense 6 becomes available worldwide to iOS and Android.