The best Engine: Doom engine (id Tech 1) games

Doom 2 is the sequel to the much acclaimed FPS Doom. Doom 2: Hell on Earth is a horror sci-fi first-person shooter created by id Software, (John Carmack, Sandy Petersen, John Romero) set on a hellish Earth invaded by demons. The player must find his way in 32 levels, shooting down monsters and picking up keys in order to unlock new areas.