Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

Deflector (5 points): Deflect 7 discs or chasers.
High Score (5 points): Get first place on in-game score board using default settings.
Fearless (10 points): Derezz Sark 4 times without using your deflector.
Rock Steady (10 points): Derezz Sark once without moving.
One Shot (10 points): Derezz Sark 3 times by only throwing one disc at a time.
Sharp Shooter (10 points): Destroy 5 enemy discs in the air in a row.
On the Run (10 points): Stay alive for one minute without getting hit or throwing a disc.
Chaser Shooter (15 points): Destroy 5 Chasers or Super Chasers.
Speed Master (20 points): Win 5 Speed Versus games over Xbox Live.
Teamwork! (25 points): Achieve a score of 50,000 or more playing an Xbox Live Co-op game.
50k (35 points): Rack up 50,000 points using default settings.
Immortal (45 points): Rack up 60,000 points without dying.