3-Demon

3-Demon (also known as Monster Maze) is a wire-frame maze game for MS-DOS based on "Pac-Man". It was released by PC Research in 1983 as shareware.
Gameplay.
The player moves through a wire-frame 3-D maze in first-person perspective, eating pellets and avoiding red ghosts. Eating a power pellet turns the ghosts green and gives the player the ability to eat them for extra points. The difficulty increases for each level completed. Unlike "Pac-Man", the player isn't required to eat all the pellets, but an increasing percentage for every level completed. The player can gain bonus points by eating extra pellets over the level requirement and skip to the next level at any point (which can be used to avoid ghosts when trapped), being automatically advanced upon eating all pellets in the level. The music is by Scott Joplin.