Level Skip:
At the LucasArts logo at the beginning of the game, Press Up + Fire, Down + Fire, Left + Fire, Right + Fire. If done correctly, you'll hear a phone ringing and a voice answering "LucasArts" Once activated, you can skip to any level by pressing:

Level Select:
Buttons 1-9 Go to the respective levels
Buttons a-h Goes to the rest of the chapters (a goes to 10; b goes to 11, etc.)

Repair Damage:
Press + during game play.

View next FMV sequence:
Press "Esc" button during game play.