DOOM

In the future, humans have left Earth and settled throughout the galaxy. On Mars, the Union Aerospace Corporation has built a radioactive waste facility and allowed the military to conduct teleportation experiments on the nearby moons Deimos and Phobos. A few hours ago, the Mars base began receiving disjointed distress calls from Phobos, while Deimos has completely vanished. Since all attempts to make contact have failed, you and your team have been dispatched to investigate. Upon your arrival, you secure the perimeter while the rest of your team enters the facility. While you stand guard, your radio crackles with the sound of gunfire, snapping bones, and blood-curdling screams before finally falling silent. Alone, with no way to leave the planet, and with no means of defense other than your trusty pistol, there is only one way out—into the complex of death and the horrors that await you there. If you plan to get out of here alive, you’ll have to fend off hordes of demonic goblins, haunting ghosts, and your undead former comrades, who are just waiting to tear you to pieces. So grab the nearest shotgun and shoot your way out of this damn madness!

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.