Rockin' Kats isn't really that tough of a game, especially when you can refill your HP any time you want. But, you still have to play through the game to see the ending, which could take a while.

Or, you could go to the password entry screen and put in this password:

Which will take you directly to the (rather silly) ending sequence.

Which is great if you're borrowing the game and don't quite make it to the end before you have to take it back.