Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
Egg-stra XP! (20 points)	Complete the Egg-Stra XP challenge and then destroy a hive in the Onslaught DLC package.
Nightfall Completionist (30 points)	Complete all challenges and kill the Breeder in Nightfall.
Pea Shooter (20 points)	Kill a Rhino with only a pistol in Nightfall.
Phantom Exterminator (20 points)	Kill 5 Phantoms in one game.
Pushing Ahead (20 points)	Gain access to the Compound area in Nightfall.
Speed Slayer (20 points)	Kill the Breeder in less than 5 minutes in Nightfall.
Survived Nightfall (20 points)	Kill the Breeder for the first time in Nightfall.
Throttled Survival (30 points)	Kill the Breeder while using a Relic in Nightfall.
Turnabout is Fair Play (20 points)	Kill 50 Cryptids with the Venom-X weapon in Nightfall.
Undiscovered Truths (30 points)	Found all intels.
Weapon Facility (20 points)	Gain access to the Facility in Nightfall.