Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
Duty accomplishment ratio 20% ( 50 points )	Complete 20% of all missions.
Duty accomplishment ratio 40% ( 75 points )	Complete 40% of all missions.
Duty accomplishment ratio 60% ( 100 points )	Complete 60% of all missions.
Duty accomplishment ratio 80% ( 125 points )	Complete 80% of all missions.
Duty accomplishment ratio 100% ( 200 points )	Complete 100% of all missions.
UNKNOWN-1 Defeat ( 100 points )	Defeat Unknown-1.
UNKNOWN-2 Defeat ( 150 points )	Defeat Unknown-2.
UNKNOWN-3 Defeat ( 200 points )	Defeat Unknown-3.