DOOM

Story

The player takes on the role of a marine (unnamed to represent the player persona), "one of Earth's toughest, hardened in battle and trained for action", who was imprisoned on Mars after attacking a senior officer when he was ordered to fire on civilians. There he works for the Union Aerospace Corporation (UAC), a multiplanetary conglomerate and military corporation that conducts secret experiments on interdimensional travel. Lately, the teleportation has shown signs of anomalies and instability, but the research continues nonetheless. Suddenly something goes wrong and creatures from hell pour out of the teleportation gates on Deimos and Phobos. A defensive response by the bases' security forces fails to stop the invasion and the bases are quickly overrun by the monsters; all personnel are killed or turned into zombies A military commando from Mars travels to Phobos to investigate the incident. The player is tasked with securing the perimeter while the assault team and their heavy weapons are brought inside. Soon radio contact is lost and the player realizes that he is the only survivor. Unable to pilot the shuttle off Phobos on his own, the only way to escape is to go inside and fight his way through the moon base complexes.