Alien 3: The Gun is a 1993 light gun arcade game published by Sega and based on the 1992 film Alien 3.
In an alternate plot of the movie, two Colonial Marines are sent to the USS Sulaco to rescue survivors, only to crash land on Fiorina "Fury" 161 after fighting a Super Facehugger. They discover that "Fury" has been infested by hundreds - possibly even thousands - of Runners. They kill countless xenomorphs, rescuing prisoners until they met the aliens' "Big Boss" (the alien from the movie). The Marines destroy the planet's defense systems, programmed by the Weyland-Yutani corporation. They eventually kill the "Big Boss", where they meet an unknown man. The Marines kill the man, only to be confronted a squad of commandos. The records of the incident on Fury 161 are removed, and the facility there is closed and almost forgotten. The USCM removes two names from the Colonial Marine ranks. The "names" are the player Marines. They are implied to be M.I.A., as no one knows if they're dead or alive.