Crazy Hard Difficulty
Highlight the "Level" selection on the setup screen. Press Left(2), Right(2), Down, Up, Down, Up, A, X. The "Crazy Hard" selection will appear.
Sound Test
Highlight the "Sound" selection on the setup screen. Press Select to stop the current song. Press various buttons to play different sounds.
Level Select
Press A(3), B, Y, R, Select, L, Down, Up, Down, Right. The copyright and licensing screen will appear with the level number.