Cheat Menu
Enter the password "GTGAUO". Now land your plane for a surprise. After that, hit b+c at the same time and it will take you to a screen at the top of that page. Some words will be highlighted bring the green highlight down to where it says unlimited ammo. There are a few more cheats also make it so you see a little x beside it and you will have those cheats.
Cheat mode
Press B + C during game play. A menu with unlimited firepower, invincibility, automatic targeting, and other options will be displayed.
Harder Game
For a real challenge, at the password screen, enter the password "GPRJCM". You'll face an aerial onslaught of F-22's, KC-135's and MIGs.
Cheat Menu...