If You complete the indicated task You'll get the allotted gamerscore.
Flying Ace (30) - Reach Flying Ace Status (Xbox LIVE Player Match Only).
Classic (25) - Earn Doghouse reward 10 times (Multiplayer Only).
Veteran (25) - Earn 10,000+ points (Xbox LIVE Player Match Only).
Sky King (20) - Earn 25 wins (Multiplayer Only).
Weaponeer (20) - Earn 25+ kills with every secondary weapon.
Big Guns (15) - Earn 100 kills from the Turret.
Flawless (15) - Complete any mode with 20+ kills and no deaths (Multiplayer Only).
Helping Hand (15) - Earn 250 assists.
Hero (10) - Earn gold medals on all Defense Missions (Headquarters, Big Guns, and Reconnaissance).
Professional (10) - Earn gold medals on all Assault Missions (Bully Fight, Zeppeligeddon, and Bombs Away).
Technical (10) - Earn gold medals on all Navigation Missions (Ring Race, Birds of War, and Follow the Leader).
Cadet (5) - Complete a game of Dogfight.