Ninja Kiwi, a small New Zealand studio, had already found modest success with a simple physics-artillery game called Bloons, where players popped rows of balloons with well-aimed darts. In 2007 the studio repurposed that same cheerful cartoon world — monkeys, darts, and candy-colored balloons — into a tower defense game, and Bloons Tower Defense grew into one of the format's most recognizable and long-running franchises.
From Artillery Game to Tower Defense
Bloons Tower Defense kept the original game's dart-throwing monkeys but rebuilt the core loop around placing stationary towers along a fixed path, upgrading them between waves, and popping ever-tougher lines of "bloons" before they reached the exit. It arrived on Newgrounds just as the tower defense genre itself was exploding in popularity, and its charm and approachability helped it stand out from the more technical, grid-based defense games crowding browser portals at the time.
A Genre-Defining Sequel Machine
What set Bloons apart from most of its Flash contemporaries was its willingness to keep iterating. Bloons TD 2 through 6, plus the multiplayer spin-off Bloons TD Battles, steadily layered on new tower types, upgrade paths, and special hero monkeys, while never abandoning the original's cheerful, low-stakes tone. That consistency let Ninja Kiwi carry the franchise across nearly two decades, from a single Flash file on Newgrounds to a full mobile and PC franchise still receiving new content today.
Long after Flash Player itself was retired, Bloons Tower Defense's balloon-popping monkeys kept marching, a rare example of a browser game franchise that never needed to leave its own universe to survive.