Banana

Level skip:
Select level 46 at the title screen. Press A + B to lose all your lives and end the game. When the title screen re-appears, select any level. Press Up + B + A on controller two during game play to advance to the next level.

Cheat mode:
Hold Select + Start at the main menu to display the password prompt. Then, enter one of the following passwords to activate the corresponding cheat function.

Level 100:
Enter 7331-4754-1337 as a password.

Level 101:
Enter 7672-6969-7331 as a password.

Levels 102-110 (secret):
Enter 4647-09NN-OLRY as a password.

Red, blue and green bananas:
Enter FHJF-FJ87-PO90 as a password.