Remove text during replay
Hold X + Y during replay.

Never lose money
After each mission save your game. If you lose your plane in the following mission, reload what you saved and you'll have the plane you just lost and the same amount of money.

Bonus Fighters
Complete all twenty missions to unlock the following fighters: Sea Harrier, AV-8B Harrier II, F/A-18C Hornet, F-15E Strike Eagle, Su-27B Flanker, Su-34 Platypus, S-37 Berkut, MiG-1.44 MFI. NOTE: To get the S-37, beat the game on easy. To get the MFI, beat the game on normal.

Quick Money
Shoot down any required aerial target with guns and not missles and the bounty you get for it doubles.

Pass through objects
Pause the game before your plane hits an object. Then B + Y to change the camera angle. Resume game.

Special Options
Complete all twenty missions under the normal difficulty setting to unlock a "Special" selection on the options menu. The new options allow unlimited missiles and the HUD display to be removed.

Fly EE Lightening
Complete the game at Hard difficulty.