Bloons TD Review: The Tower Defense Standard

Tower defense was a Flash-era genre that should have died with Flash. Ninja Kiwi’s Bloons series didn’t get that memo. From the 2007 original through Bloons TD 6 (still receiving updates), the New Zealand studio has shipped what’s arguably the most refined tower defense franchise in any medium. This bloons td review covers what works, what’s aged, and which entry to start with. Short answer: strongly recommended, and Bloons TD 6 is the one to play.

What Bloons TD is

Bloons Tower Defense (BTD) is a series where waves of colorful balloons (bloons) follow a fixed path through a level. You place monkey towers along the path to pop them before they reach the exit. Different bloon types have different defenses — black bloons immune to explosions, white bloons immune to freezing, lead bloons immune to sharp projectiles, regrow bloons that heal back to higher tiers. Tower upgrades, monkey heroes, and game modes give the franchise its depth.

The franchise spans BTD 1 (2007) through BTD 6 (2018, still updated), plus spinoffs. The early entries were Flash games, and since Flash ended in December 2020 they’re no longer playable on Ninja Kiwi’s website; the classics are collected in the free Ninja Kiwi Archive app for desktop (on Steam), and BTD 5 is also sold as a standalone download. BTD 6 is a separate purchase on PC, mobile, and consoles. For more on the franchise’s origins, see our Bloons TD history.

How it plays

Open the game, pick a map, click start. The map has a fixed path. You spend cash to place monkey towers along the path. Towers automatically attack bloons in range. Each tower has upgrade paths that improve damage, range, attack speed, or unlock special abilities. After each round, you earn more cash to spend on more towers or upgrades.

Rounds escalate. Round 1 is a few red bloons. In BTD 6 the first MOAB (a massive armored blimp that takes dozens of hits and releases more bloons when popped) shows up around round 40, and by round 100 you’re facing the biggest blimps in the game. The escalation is the entire arc.

What makes it work

The upgrade tree depth is enormous

In BTD 6, each monkey tower has three upgrade paths with five tiers each (BTD 5 used two paths of four tiers). Tier 5 upgrades are game-changers — True Sun God, Avatar of Wrath, MOAB Eliminator. The total combination space is huge, and different strategies dominate different rounds.

BTD 6’s hero system adds variety

BTD 6 introduced heroes, and the roster has grown well past a dozen, each with unique abilities and a leveling path. Quincy the archer plays differently from Gwendolin the pyromancer who plays differently from Adora the priestess. Heroes change strategy fundamentally and add replay value.

The bloon variety creates real puzzles

Lead bloons are immune to sharp projectiles. Camo bloons can’t be targeted by most towers without detection upgrades. Purple bloons are immune to energy, fire and plasma attacks. Each composition requires different counter-towers. Mid-game rounds are real puzzles, not just damage races.

Ninja Kiwi keeps the franchise alive

Bloons TD 6 still gets regular content updates. New heroes, maps, modes, and balance changes keep shipping. Few games of any kind sustain this level of post-launch support this many years in.

What doesn’t work

The older entries (BTD 1–4) feel dated compared to BTD 5 and 6. The upgrade trees are shallower, the visuals are more basic, and the bloon variety is limited. They’re playable but inferior.

BTD 6 has monetization. The base game is paid (one-time purchase) and includes optional cosmetic and convenience purchases. Some players bounce off the paid entry point. The free Ninja Kiwi Archive, with the classic entries, is the no-cost alternative.

The difficulty curve in BTD 6 can spike on harder maps and modes. Modes such as Magic Monkeys Only or Double HP MOABs assume deep knowledge of tower interactions. New players coming straight to the hardest content will be lost.

Many players find the touch controls on mobile the most natural fit for tower placement, while the PC version suits players who prefer mouse precision and hotkeys. Both are full versions of the game.

Who it’s for

Bloons TD is for tower defense fans of any stripe. It’s for puzzle-strategy players who want depth. It’s for casual players who want a relaxed match. The franchise has an entry point for almost every preference.

It’s not for people who actively dislike tower defense. The genre conventions are inescapable — fixed paths, wave timers, tower placement. If you don’t like the loop, the depth won’t save you.

Comparison with the wider scene

Bloons TD’s direct competitors include Kingdom Rush (Ironhide Game Studio), Plants vs. Zombies, and the GemCraft series. Kingdom Rush has stronger production values; Plants vs. Zombies has wider mainstream appeal; GemCraft has deeper customization. Bloons TD’s strength is upgrade depth, bloon-type puzzles, and franchise longevity.

BTD 6 in particular sits at the top of the contemporary tower defense scene. Few other games in the genre have matched its content update cadence or its depth of strategic combinations.

The verdict

Strongly recommended. Bloons TD is the most refined tower defense franchise in any medium. The upgrade depth, bloon variety, and hero system give BTD 6 more strategic content than most full-priced strategy games. Ninja Kiwi’s continued support makes it a genuinely growing game.

The caveats: BTD 6 is paid (a one-time purchase, not subscription); older entries are dated; monetization in BTD 6 exists. Try the classics in the free Ninja Kiwi Archive if you want free, BTD 6 on mobile or PC if you want the current peak. As a tower defense pick, the bloons td review of “still the genre standard” understates it. It’s the genre standard by a comfortable margin.

Frequently asked questions

Which Bloons TD is the best?

Bloons TD 6 (2018) is the current peak. It has the deepest upgrade trees, the hero system, and continued content updates. Bloons TD 5 is the strongest of the older entries. The earlier Flash entries are playable through the Ninja Kiwi Archive but lack the depth of BTD 5 and 6.

Is Bloons TD free?

Partly. The Ninja Kiwi Archive is a free desktop app on Steam that collects many of the classic Flash-era games. BTD 5 and BTD 6 are paid downloads, and BTD 6 also includes optional cosmetic and convenience purchases. The original browser versions stopped working on the web when Flash ended in 2020.

How long does it take to beat Bloons TD 6?

A casual run through the maps easily takes dozens of hours. Completing every map on every difficulty (including CHIMPS mode) takes far longer. The content keeps expanding with updates, so “beating” the game is a moving target.

What’s the difference between Bloons TD 5 and 6?

BTD 6 added the hero system, a third upgrade path and tier 5 upgrades (later, paragon towers), 3D graphics, and Monkey Knowledge progression. BTD 5 has the classic gameplay without those layers. BTD 6 is deeper; BTD 5 is faster to learn.

Who made Bloons TD?

Ninja Kiwi, a game studio based in Auckland, New Zealand, founded by brothers Chris and Stephen Harris. They’ve developed the Bloons franchise since the original Bloons (a non-TD dart-throwing puzzle game) in 2007. Since 2021 the studio has been owned by the Swedish games group MTG.

The bottom line

Bloons TD is the tower defense franchise other studios benchmark against. BTD 6 is the current peak, the free Ninja Kiwi Archive keeps the classics alive, and Ninja Kiwi keeps the lights on with regular updates. If you have any interest in tower defense, this is where to start. For a single-player palate cleanser between MOAB waves, the T-Rex Runner runs in a browser tab without any tower placement decisions.

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