Complete the following achievements to unlock Microsoft Gamerscore points.

Achievement	How to unlock
One Small Step (50 points)	Destroy a Bomber boss.
Giant Leap (50 points)	Destroy a Frigate boss.
LASER!$ (50 points)	Destroy a Destroyer boss.
A bit closer to Heaven (50 points)	Destroy a Cruiser boss.
They're everywhere (50 points)	Destroy a Carrier boss.
The Bullets before the Storm (50 points)	Destroy a Battleship boss.
Kiss Of Death (50 points)	Meet the Mothership.
The Beginning and The End. (50 points)	Destroy the Mothership.
Rebel (100 points)	Destroy the Nemesis.