I got this game the day it came out here - definitely worth it. It's really an amazing game, and it should last you for 30-40 hours of playing.
It's got a great art style, great music, great story and lots to do... it's what Zelda: TP *should* have been. (There's lots of similarities in the game to Zelda, but imo Okami pulls everything off a lot better than Zelda)
It's officially my favourite game ever :p