Hold Nunchuck Up at the "Unlockables" screen until the code entry prompt appears. Then, enter one of the following codes on the Wiimote to activate the corresponding cheat function.

Unlockable	How to unlock
Level select	Up Right Down Right Up
Lots Of Guns	Right Left Down Left Up
Can't Be Killed	LDURU
Crypto Dance Fever Skin	Right Left Right Left Up
Infinite Ammo	Right Up Up Left Right
Infinite Jetpack	Right Right Up Left Left
Kluckin's Chicken Blimp Skin	LUDUD
Stealth Space Ninja	Up Right Down Down Left
Unlimited Big Willy Battery	Left Left Up Right Down