Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
All Mine ( 20 points )	Kill all other players in an 8-player Deathmatch.
Berserker ( 30 points )	Obtain the rank of Berserker.
Commando ( 20 points )	Obtain the rank of Commando.
Cut a Rug ( 20 points )	Land 100 full combo attacks. (3 consecutive hits)
Elite ( 20 points )	Obtain the rank of Elite.
Headache ( 20 points )	Kill 200 enemies with headshots.
Hunter ( 10 points )	Kill 500 enemies.
Immortal ( 50 points )	Obtain the rank of Immortal.
Killing Spree ( 20 points )	Kill 20 opponents in one match.
Leave Me Alone! ( 50 points )	Destroy 50 Watchers. (50/50)
Lone Gunman ( 20 points )	Kill all members of the opposing team alone. (8-player Team Battle)
Major League ( 20 points )	Land 200 combo throws.
Mercenary ( 20 points )	Obtain the rank of Mercenary.
Ninja Style ( 20 points )	Filena killed 50 enemies.
Novice ( 5 points )	Obtain the rank of Novice.
On a Roll ( 20 points )	Kill 10 opponents in a row during one match.
Predator ( 50 points )	Kill 1000 enemies.
Privacy Issues ( 10 points )	Destroy 1 Watcher. (1/50)
Slayer ( 20 points )	Obtain the rank of Slayer.
Soldier ( 10 points )	Obtain the rank of Soldier.
Stop Looking At Me! ( 30 points )	Destroy 20 Watchers. (20/50)
Storm ( 30 points )	Obtain the rank of Storm.
Triage ( 20 points )	Revive 10 teammates in one match.