Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
Bigfoot (20 points)	In Crimson DLC matchmaking, kill 20 enemies using the Mantis' stomp attack.
Clay Pigeon (40 points)	In Crimson DLC matchmaking, shoot an enemy who's airborne from a Man Cannon.
David and Goliath (20 points)	In Crimson DLC matchmaking, board an enemy Mantis.
Now They Fly? (50 points)	In Crimson DLC matchmaking, get a kill while airborne in a Warthog.
ODST (30 points)	In Crimson DLC matchmaking, kill a player while airborne from a Man Cannon.
Pump Yer Brakes (40 points)	In Crimson DLC matchmaking, score the killing blow on a Mantis.
Size is Everything (20 points)	In Crimson DLC matchmaking, kill 20 enemies with a detached Machine Gun Turret.
Special Delivery (30 points)	In Crimson DLC matchmaking, kill an enemy with melee when landing from a Man Cannon.