Cheats
At the start game screen, pick the icon then enter the cheat:

Icon:Taz, Code: !WB Disables whack in the boxes 
Icon: Big red, Code: *JC Opens 2 player boss games 
Icon:Tweety, Code: .RT Opens all of the art gallery 
Icon: Daffy Duck, Code: ?BN Unlocks all mini games 
Icon: Marvin the Martian, Code: #OP Unlocks all levels