AI-made tower defense games

Tower defense is a strategy subgenre where the goal is to defend territory by obstructing attackers or stopping enemies from reaching the exits. The core loop is to place defenses along an enemy path, survive a wave, earn currency for defeated enemies, and upgrade or repair before the next wave. Plants vs. Zombies (2009) and Bloons Tower Defense are well-known examples.

The code is mostly wave scripting and pathfinding. Enemies follow set paths or find routes around the towers players place, and each wave defines enemy types, counts and timing. Some games let players lengthen the route by building mazes, and currency, costs and wave difficulty need balancing.

In a browser, pointer events let players place towers with a click or a tap, and pathfinding for large waves can run in a Web Worker so the main thread isn't slowed down.