Cheat mode:
Hold Up/Left and reset the NES system. Quickly press A + B + Select, A + B + Select while the screen remains blank. A configuration screen with level and difficulty selection features will appear.

Level skip:
Pause game play, press Up/Left, A + B + Select. Your jet will fly away and complete the level when game play is resumed.

Additional time:
Get a valid password, then reset the NES. Enter the password, but change the first number to the amount of desired days, from 0 to 60, plus 40.

Final level:
Enter 88 60 72 as a password.