Complete the following achievements to unlock Microsoft Gamerscore points.

Achievement	How to unlock
100% Completion (200 points)	Find everything in the game.
After you... (50 points)	Reach ending #2.
Close Encounter (50 points)	Meet someone unexpected.
Fast Mover (125 points)	Complete the game in less than 3 hours.
Game Complete (125 points)	Complete the game.
Hey man, nice shot! (125 points)	Shoot a worm while it's falling.
Let's blow this joint (50 points)	Get ready to make your own way out of the mining base.
Say hello... (125 points)	Find the grenade launcher.
See the local wildlife (50 points)	Get up close and personal with some of the local creatures.
Selfless (50 points)	Reach ending #1.
Where is everyone? (50 points)	Find a member of your crew.