Unlock Microsoft Gamerscore points, by completing the following Achievements.

Achievement	How to unlock
Artful Dodger ( 5 points )	Complete a "No Damage" challenge.
Eye Candy ( 15 points )	Take over the prefrontal cortex.
Eye for an Eye ( 10 points )	Kill the King of the spleen.
In a Nut Shell ( 15 points )	Take over the duodenum.
Jack the Ripper ( 5 points )	Rip out an eye.
Limbo ( 5 points )	Complete a level without collecting any pickups at all.
Mr. Immortal ( 10 points )	Complete all levels without dying.
Napoleon ( 20 points )	Get 3 stars on all levels.
Perfection ( 5 points )	Make a perfect run.
Pickup Truck ( 10 points )	Collect all pickups in the game.
Play it Safe ( 10 points )	Complete a level without taking any damage.
Shell Out ( 10 points )	Kill Mama Amygdala.
Slay Away ( 10 points )	Eat 5 eyes super fast!.
Slice N' Dice ( 15 points )	Defeat Papa Cerebellum.
Soupe a'la Turtle ( 5 points )	Kill a Turtlepoodle.
Speed Devil ( 5 points )	Complete a time challenge.
Tentaculous ( 20 points )	Complete the game.
The Small Escape ( 10 points )	Escape Dr. Phluff's acid attack.
When I Say Jump ( 10 points )	Complete all challenges.
Worm Eater ( 5 points )	Defeat the Queen of the Colon.