How would that work? They'd have to massively slow down Sonic. It'd be cool though if they made his specialty to parkour on walls and such during levels.
They could make it so that he can't use power-ups, but can use parkour (Cat Suit) and the Homing Attack. And make him a bit faster than Toad. Maybe let him pick up speed on slopes?
Oh ok. I was asking it because I cannot buy anything from Club Nintendo because none of countries where I have apartment are listed on European Club Nintendo.