Hit sloth with your cannon until she turns into water. Quickly go and transmute her into ice and attack her with any attack. Repeat until dead.
Beat the game to unlock Character mode.
You can tickle the Menu characters!
Poke Ed(for example) with the stylus he'll move.
If you RUB him with the stylus he'll laugh then Growl then scream at you. The same goes for everyone else except they do different things!
To unlock Hard mode, beat the game.