Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

Private (5 points): Destroy a Super Tank Classic game in Normal difficulty.
Specialist (5 points): Destroy a Tank by piloting a Missile Multiplayer game in Ranked match.
Maniac (10 points): Score 50,000 Classic game in Throttle Monkey mode.
Corporal (10 points): Score 100,000 Classic game in Normal difficulty.
Sergeant (10 points): Win a game Multiplayer game in Ranked match.
Ensign (15 points): Destroy 10 Saucers Evolved game in Normal difficulty.
Lieutenant (15 points): Have 5 lives in hand Evolved game in Normal difficulty.
Commander (20 points): Get a 5-frag killing spree Multiplayer game in Ranked match.
Captain (25 points): Destroy 10 missiles in 1 game Classic game in Normal difficulty.
Major (25 points): Win a game without dying Multiplayer game in Ranked match.
Colonel (30 points): Have three enemies in play at once Evolved game in Normal difficulty.
General (30 points): Score 1,000,000 Classic game in Normal difficulty.