Stage Select

Go to the jukebox mode and place the red checker on the following numbers in order, pressing C at each one:

14, 15, 18, 5, 13, 1, 3, 18, 15, 6.

Now, highlight a number from 1 to 6 and press C to warp to the corresponding stage.
View Credits

At the Options Mode enter the following code...

Press A + B + C

Then as soon as you press them you should view the credits.
Unlimited health

If you want unlimited go to jukebox in the options menu and push C on these numbers.3, 12,17,2, 2, 10, 2, 7, 7,11.You should hear skecth say ''oh yeah''.