Unlock Xbox Live Gamerscore points, by completing the following Achievements.

Achievement	How to unlock
In a Foreign Land ( 20 points )	Scout the Zion Valley for signs of the White Legs.
May my Hand Forget its Skill ( 40 points )	Evacuate Zion.
O Daughter of Babylon ( 30 points )	Crush the White Legs.
Restore Our Fortunes ( 30 points )	Resupply Daniel and the Sorrows.
When We Remembered Zion ( 20 points )	Arrive at Zion.