To unlock all campaign missions and planes, go to the main menu, hold L1 + R1 and press Square, L2, R2, Triangle(2), R2, L2, Square.
To become invincible, pause the game, then hold L1 and press Square, Triangle(2), Square. Then, hold R1 and quickly press Triangle, Square(2), Triangle.
To increase damage, pause the game, then hold L1 and press L2(2), R2. Next, hold R1 and press R2(2), L2.
To unlock Ace Killer, you have to defeat all the other Aces.
To unclok Ace of Aces, you should get the highest score in all Campaign missions.