Cheat codes:
     Position yourself on the title screen and hold start and press Y,
A, B, B, Y, A, X, B, X, B.
     Now  press X to display the Level Select screen. Now you can also
use any of the following:

Skip Level
     Hold L + Start + Y, during gameplay.

God Mode
     Hold L + Start + X, during gameplay.

Get Everything
     Hold L + Start + A, during gameplay.