Enter one of the following player names at the main menu, then press CTRL + RIGHT SHIFT + 8 to display the cheat menu with the corresponding options. Each player name will select which options appear on the menu:

OPTIONS - PLAYER NAME
Invincible - LIVE FREE
City, Tourist, Demo cam, No time - TOURIST
Select level - FOX ROX
Select plane - MR HAPPY
Damage bonus, Weapons, Fast reload - GO POSTAL
Select level, plane; Invincible, Weapons, Fast reload - KIWI
Kill civil, Kill wing - GODZILLA
All options - KYRA NR
All options - BRENDAN QR
All options - DOOFUS
All options - GREG FM
All options - SCOTTYWAR
All options - ROSA DUONG
All options - COCO
All options - RADARMY
All options - DAB DAB
All options - TRI S

Note:
-The fast reload option allows missiles to be rapidly fired.
-The damage bonus option allows aliens, generators, and vehicles to be destroyed with a single shot.
-The weapons options allows your plane to have unlimited firepower.
-The kill civ option allows civilian ground targets to be hit.
-The kill wing option allows you to shoot down your wingman.