During gameplay press 'Start' to pause the game and then hold down the L button. When the words 'Cheat Mode' appear on screen enter the code for the effect you want while still holding the L button, if you've entered the code correctly the words 'Cheat Mode' will flash as confirmation. There is a limit of three cheat codes per 'Save' file and to be able to skip a level you must be on it.

Skip 'Rabbit Land':
Press Start, Select, B, A, Up.

Skip 'Bever Land':
Press Start, Select, B, A, Right.

Skip 'Duck Land':
Press Start, Select, B, A, Left.

Skip 'Skunk Land':
Press Start, Select, B, A, Down.

Skip 'Squirrel Land':
Press Start, Select, B, A, B.

Unlock 30 Woo-Hoo Bars:
Up, Right, Down, Left, Up, Select, Start.

Get 3 Extra Lives:
Up, Up, Down, Down, Left, Right, Left, Right, B, A, Start.