Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
Clever Girls ( 10 points )	Survive your first encounter with Stalkers.
Cross your Heart, Hope to Die ( 30 points )	Survive the Eye Poke Machine.
Derailed ( 20 points )	Survive the Train Sequence.
Elevator Action ( 15 points )	Knock off every Tripod during the Elevator Sequence.
Hornet's Nest ( 30 points )	Destroy the Tripod Nest.
Knock Knock ( 25 points )	Complete the Drill Ride.
One Small Step ( 10 points )	Get through the first Zero-G area.
Operation! ( 15 points )	Snare the Shard with the Ishimura.
Patient on the Loose ( 15 points )	Get your first Suit.
Powered Up ( 15 points )	Complete the Solar Array Puzzle.
Shut Down ( 10 points )	Defeat the AI.
The Final Sacrifice ( 50 points )	Destroy the Marker.
The Fugitive ( 50 points )	Escape the Facility.
The Graduate ( 20 points )	Win the fight at the School.
Torment Me No More ( 20 points )	Kill the Tormenter.