Six numbered games, one persistent idea. The Bloons Tower Defense series has run since 2007, and the jump from the first Flash game to BTD6 is larger than most series manage in twice the time. This page is the map: the timeline, the side branches, and the honest answer to "what did the sixth one change".
The mainline timeline
| # | Game | First release | Platform then | What it added | Status |
|---|---|---|---|---|---|
| 1 | Bloons Tower Defense | August 16, 2007 | Flash | The original: one map, 50 rounds, the balloon-popping loop | [partial] |
| 2 | BTD2 | October 2007 | Flash | More towers, multiple maps, difficulty medals | [partial] |
| 3 | BTD3 | September 2008 | Flash | Rebalanced difficulty, first ports to iOS and handhelds | [partial] |
| 4 | BTD4 | October 2009 | Flash | Visual overhaul, MOAB-class airships debut, first mobile version in late 2010 | [partial] |
| 5 | BTD5 | December 2011 | Flash | First co-op mode, camo and regrow bloons, Monkey Money, Special Agents | [partial] |
| 6 | BTD6 | June 2018 (mobile), December 17, 2018 (Steam) | 3D everywhere | Full 3D, heroes, three-path upgrades, Monkey Knowledge, live events | [official] |
The side branches that never took a number
Ninja Kiwi numbers only its mainline tower defense games. Bloons TD Battles (the PvP game), Bloons Monkey City, Bloons Adventure Time TD and the card game spin-offs are all part of the family, and none of them is "BTD7". That is also why a sixth numbered game can coexist with a thriving Battles 2: different genres, one universe.
The Flash generation also had a paid detour: BTD5 Deluxe, a $19.99 Windows and Mac bundle from 2012, retired in 2014 when the Steam version of BTD5 replaced it. When Flash died, Ninja Kiwi's Archive project kept the old games playable, which is why the 2007 original is not actually lost.
What BTD6 actually changed
Three things, and none of them is "better graphics" alone:
- The hero layer. BTD6 introduced heroes: seventeen named characters now, one per game, leveling automatically. Nothing in the Flash era had a persistent character system.
- The upgrade lattice. Twenty-five towers with three paths of five tiers replaced fixed tower sets, making build composition the core skill.
- The live-service shell. Boss events, Paragons, Monkey Knowledge, co-op everywhere and eight years of numbered updates turned a one-shot game into a platform that now also ships through Netflix and Apple Arcade.
The mechanics vocabulary survived intact, which is why a BTD5 veteran reads a BTD6 screen without a translator: Dart Monkey, MOAB, Camo and Regrow all mean the same thing they did in 2011. If you are arriving from another tower defense family entirely, our Kingdom Rush 6 comparison puts the two current generation-mates side by side.
FAQ
Is BTD6 a remake of BTD5?
No. It is the sixth game in the series, built new in 3D, with systems (heroes, three-path upgrades, live events) that did not exist in BTD5. The shared vocabulary makes it feel familiar; the design is new.
Why is there no BTD7?
Because Ninja Kiwi numbers mainline TD sequels, and BTD6 is still the current one after eight years of updates. The spin-offs carry their own names precisely so the numbered line stays clean.
Which Bloons TD should I play first?
BTD6. It is the most complete, still updated, and available on ten platforms. The older games are history worth knowing and the Archive keeps them playable, but BTD6 is where the series actually lives.