Complete the following tasks to unlock PlayStation 3 trophy rewards.

Trophy	How to unlock
Aliens (Bronze)	Collect all Alien Artifacts.
Close Encounter (Bronze)	Kill 10 alien Necromorphs.
Critical Mass (Bronze)	Recover the shuttle.
Drill Sergeant (Bronze)	Complete the Drill Room without taking any damage.
Hungry (Bronze)	Reach the pump room of the Waystation without alerting any Feeders.
Hydra (Bronze)	Kill the Snowbeast.
Infernal Machine (Bronze)	Reach the Alien Machine.
Intestinal Fortitude (Silver)	Defeat the Hive Mind.
Shoot for the Moon (Gold)	Defeat the Moon.
Snow Crash (Bronze)	Reach Tau Volantis.
Space Ace (Bronze)	Shoot at least 70 targets during the ride to Tau Volantis.
Space Odyssey (Bronze)	Survive your first spacewalk.
Stranger in a Strange Land (Bronze)	Complete the Prologue.
Together as One (Bronze)	Reassemble Rosetta.
Under a Buck (Bronze)	Shoot the deer head trophy in the Admiral's Quarters.
Weedkiller (Silver)	Kill 5 Cysts in the Biology Building with a single poison gas cloud.