Get this game on the PS2, because at least on that the wii-mote didn't constantly punch you with horrifically unresponsive controls, and brush strokes that need to be so precise that even when you DO preform it near perfectly it won't register! I constantly found myself getting in God knows how many positions to see which one would actually let me get the stroke right, and when you have to use the power slash, heh, well God have mercy on your soul!
I'd heard a lot of hype about this game but to be honest it wasn't anything special. Another downside is also something meant to be an upside and that's the wii remote. The brush requires accuracy but the wii remote is far from perfect.
Okami is an incredible game! I love how it uses Japanese lore and mythology. My only problem, the controls with some of the weapons are a tad faulty, save for the beads. But still, it is an awesome game!