Halo: Combat Evolved is a sci-fi first person shooter game set in an alien world shaped like a ring. Players take on the role of Master Chief, mankind's super soldier, and must combat the attacking Covenant forces. Missions involve battling enemies on foot and in vehicles with human and alien weapons, raiding underground labs for advanced technology, rescuing comrades, and sniping enemy forces. The game also allows up to four players to battle each other via split screen or team up cooperatively through single-player missions.