Cheats:

Press [F11] during the game and then type in the codes:

ISITWENTY20 Complete map
ISILETSBAIL Win the level successfully
ISIJAVANET Max shields
ISIWHEELS XCar available
ISIDRIVE All cars
ISIMAKEITSO All levels
ISIBEENTHERE Secret level available
ISIFATPACKED Homing ammo
ISISLEEP All enemies will sleep
ISIQ Invulnerability ON/OFF