Cheat mode:
Press Down(2), Up, X, Left(2), R, L, Start at the options menu. Return to the main menu and select the "Extras" option to access the cheat and level select functions.

Wireframe mode:
Change the Saturn's system date to March 13, 1998 and start the game.

Level select:
Enter HDVMKXVCK as a password to play level 50. Intentionally lose the level to choose from any previous level.