Complete the following achievements to unlock Microsoft Gamerscore points.

Achievement	How to unlock	Points
Blood-thirtsy	Eat ten downed soldiers hearts.	25
Braaaaains	Eat ten downed soldiers brains.	25
Decision	Kill or save your first downed soldier.	25
Die A Dozen Deaths	Die twelve different ways.	50
Encounter The Entity	Defeat the true final boss.	100
From My Cold Dead Hands	Get all human gun upgrades.	100
He Had to Split	Dismember fifty enemies.	50
Hero	Rescue every downed soldier.	100
Phasers on Kill	Max out alien gun upgrades.	100
Savior	Rescue ten downed soldiers.	25
Serial Killer	Kill every downed soldier.	100
Skewered	Kill three enemies in one throw.	25
Star Spore	Capture a Star Spore.	50
Stick Around	Spear enemies to the wall.	50
Tarzan	Swing a far distance without touching the ground.	50
Ultimate Weapon	Max out the ChainStaff.	100
Well Don't Take My Head Off About It	Decapitate an active soldier with the Super Spear.	25