http://uk.gamespot.com/ps2/action/okami/index.html?tag=result;title;1

Playing the PS2 version, but it is a sheer delight. After a slightly wordy intro, the game teaches you all its little nuances through a wonderful village sequence and then launches you into a Zelda-esque quest to banish the Japanese world from evil. But you play a wolf with the ability to change the way the world is shaped by drawing on the screen with a huge caligraphy pen.

Sound odd? It is a little, and the combat hasn't really been explained yet, but it's the first time in ages I've looked at a game and thought: "Wow. Bring on 40 hours of this shit..."

It's supposed to be great on the Wii too according to some folks on here and the reviews:

http://uk.gamespot.com/wii/action/okami/index.html?tag=result;title;0