Buy System Shock 2

The action-horror forerunner of the acclaimed Bioshock series, System Shock 2 is a sci-fi game that may well be an action-horror movie all on its own. 

You are a crewmember of the titanic spaceship Von Braun, sent to answer a distress call from the planet Tau Ceti V. You awaken from cryo-sleep to a ship in mayhem--mutants chasing and killing every human in sight. Somehow you must get to the bottom of this invasion and prevent it from returning to Earth. But what can you do when your only ally is the megalomaniacal AI, SHODAN?

Choose your class. Select between the Marines, a soldier with a heavy focus on weaponry; the Navy, which teaches you all you need to know about repair and hacking; or the OSA, which grants you psychic powers, including teleportation, telekinesis, or energy manipulation.  

Customize your character. By collecting cyber-modules you can determine which skills to upgrade. Wield a variety of weapons and keep them in good working order. Consider your choices well; supplies are limited, you’ll need everything you can in order to survive.

Fight an army of hostile robots, deadly turrets, and mutated crew members. Worst of all, prepare to face the abominable threat of The Many, a strange parasitic alien race melded into a psychic hive mind, who will relentlessly pursue you through the halls of the ship.

Critically-acclaimed as a game well ahead of its time, System Shock 2 proves that in space, something can hear you scream, and will come running to share in the feast.