Williams created a string of computer games from 1982 through 1990 for the Atari 8-bit family and then the Amiga which are admired for their imaginative design concepts, innovative sound and music, and skillful implementation. "Necromancer" is a three-stage game about a wizard growing and controlling an army of trees. Scenarios in "Alley Cat" include stealthily drinking from the bowls of sleeping dogs, avoiding a sweeping broom to jump inside a fish bowl, and collecting ferns atop a bookcase protected by spiders. "Mind Walker", one of the first games released for the Amiga, places the player inside the head of a physics professor gone mad.