Mutant

Mutant is a 1-player arcade game for the Apple II.

The player controls a small spaceship which can move horizontally on the bottom of the screen, and fire vertically forwards. Numerous waves of mutants appear on the screen, and the player must repeatedly shoot each monster to destroy it. As the monsters are shot, they change into different creatures, until eventually being destroyed after multiple hits. Enemies can enter from all 4 sides of the screen, including from directly behind or beside the player. The player has 3 lives, and when all are lost, it's game over.