Level Skip and Minigame...
	Secret Intro...

Enter these at the title screen.

Code	Effect
CHEAT then press F1 or F6	Level Skip or go back one.
NUDE	Boxing minigame.

At address $1e20a in memory is the following ASCII text:

IF YOU WANT TO SEE SOMETHING DIRTY PUT CODE HERE >>>>.....

Delete the five dots and replace it with the word DIRTY in all caps. Press Fire on your joystick, and the intro is replaced with one that has Lucy naked and a more offensive message.