Corridor 7: Alien Invasion was released by Capstone Software in 1994 using the Wolfenstein 3D engine. It has forty levels. A sequel using the Build engine called Corridor 8 was started but cancelled when Capstone went bankrupt in 1996. Unlike other games on the engine, the level objective requires clearing the entire floor of every monster, similar to Zero Tolerance on the Sega Genesis and Monster on the Amiga.
