View hidden introduction sequence:
Press C when the helicopter flies by on the title screen.

Five lives:
Enter TQQQLOM as a password.

Ten lives:
Enter BQQQAEZ as a password.

Hint: Use less fuel:
Fly over water to use less fuel during a mission.

Level	Password
2	KQAJJTP
3	WLLABED
4	BTOBKLW