Complete the following achievements to unlock Microsoft Gamerscore points.

Achievement	How to unlock	Points
A world without zombies - Stage One	Kill hundred enemies.	30
A world without zombies - Stage Three	Kill thousand enemies.	100
A world without zombies - Stage Two	Kill 500 enemies.	50
Acid Ghoul Boss	Defeat Acid Ghoul.	70
Aliens Boss	Defeat Aliens.	80
Flamethrower	Buy flamethrower.	40
Magnet	Buy magnet.	40
Micro SMG	Buy micro SMG.	40
Minigun	Buy minigun.	40
RPG	Get RPG.	50
Second pistol	Buy second pistol.	40
Shotgun	Buy shotgun.	40
Sterozombie Boss	Defeat Sterozombie.	70
Winner!	Complete game.	90
Zombactor Boss	Defeat Zombactor.	80
Zombrain Boss	Defeat Zombrain.	70
Zomsquad Boss	Defeat Zomsquad.	70