Wall-Defender, released in 1983, is a single-player shoot ’em up game designed for the Atari 2600. In this game, the player is responsible for defending a fortress consisting of multiple walls from relentless alien kamikaze assaults. Players control a character that moves along the walls, firing missiles to eliminate incoming attackers.
The exterior wall can withstand up to ten hits from regular enemies, while “super” enemies have the ability to demolish a wall in just one strike. As walls take damage, their colors change to signify their weakening state, and they begin to flash after the seventh hit from a standard attacker. Successfully destroying an entire wave of enemies without any contact grants the player an additional wall.
When a wall is on the verge of collapse, the player must retreat to an inner wall to avoid being crushed and losing the game.