=>Give Up Screen: Go to inventory screen and press a and b simultaneously. 

"Give Up" will appear. Choose it to start over again.
=>Invincibility:
1]
In a 2-player game, play through to Zone I, the office.
2]
In the room with the Zipper, do the following: Break open the Zipper crate
with Chip (it also works with Dale) then execute the "Give up screen"
code above. Chip will then die.
3]
Move Dale through the rest of the stage while Chip is floating along in 

his balloon.
4]
At the very end of the stage, before the door to the boss, Chip's balloon 

will break. He will now be invincible from the Zipper he collected previously.
5]
Enter the door to the boss chamber and Chip will have unlimited invincibility
throughout the entire boss fight.