Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
A Taste of Things to Come ( 10 points )	Build a combo weapon.
A bigger taste... ( 20 points )	Build all available combo weapons.
Chop Shop ( 20 points )	Defeat Jed the Mechanic.
Clueless No More ( 10 points )	Purchase a clue from Dick, the pawnshop owner.
Locksmith ( 20 points )	Unlock all the doors in Still Creek.
Part Way There ( 10 points )	Find and return a bike part.
Ready to Ride ( 20 points )	Rebuild the bike.
Small Town, Deep Pockets ( 20 points )	Spend $100,000 in the pawnshop.
Still Creek Savior ( 20 points )	Save all the survivors in Still Creek.
We Ride To Fortune City! ( 20 points )	Escape Still Creek with Katey.
Zombie Exterminator ( 20 points )	Kill 1,000 zombies.
Zombie Hunter ( 10 points )	Kill 100 zombies.