Catacomb Abyss is a sequel to Catacomb 3-D, an early first person shooter developed by id Software. Catacomb Abyss was released as shareware. It features a wizard who travels through levels fighting zombies, demons, and other occult creatures on his way to confront this evil rival, known simply as Nemesis. To advance he must collect keys and potions. Outside of cut scenes, the player never sees the wizard they control. Only his hand, which throws out magic fireballs, and his face which shows damage, are visible.
This game was the forerunner of Wolfenstein 3D.