Unlockable: Achievements

You can unlock the listed gamescore by completeing the related achievement.

Ace (20) - Earn 185,000 points.
Diplomat (15) - Complete a level without firing.
Epic Warrior (10) - Form a four-ship (epic) formation.
Exterminator (15) - Destroy all enemies in a level.
Halfway Point (5) - Finish Mission 3 on any difficulty.
Hero (25) - Complete the game on Normal.
Immortal (15) - Complete a level without dying or losing allies.
Legend (50) - Complete the game on Insane.
Rookie (5) - Earn 30,000 points.
Teamwork (15) - Score 10,000 points while attached in a level.
Untouchable (15) - Complete a level without taking damage.
Veteran (10) - Earn 100,000 points.

Unlockable: Stage Select

You must finish the game on insane difficulty.