I am lazy and will take the description from amazon:
In Okami, the legendary monster Orochi has come back to life and turned the world into a veritable wasteland. Players become a wolf, an embodiment of the sun god Amaterasu — the world lies in gamer’s hands as they fight ominous beings and reclaim the earth from a curse that plagues it. It is crucial to help Amaterasu make the world a place where all living creatures can dwell once again.
Amaterasu has weapons (reflector, rosary, glaive with upgrades and special attacks) and also learns brush strokes along the way; these allow Amateratu to turn day into night and back into day, slash through rocks and trees, grow trees and flowers, cross water on lily pads, use (and eventually summon) existing elements (water, fire, wind, lightening, ice), set bombs, climb walls, slow time, etc. They can be used in battle and to solve puzzles, interact with NPCs, and interact with the environment in other ways. There are animals to feed and fish to catch and treasures to find, and there are various items that give special powers. The art is stunning; it is cel-shaded in the manner of traditional Japanese paintings; the information screens are explicitly scrolls.
This was the third time through, chosen partly because my dying PS2 will read it (wanted either katamari, but it wouldn’t read either disc); partly because, the last time, I got all the stray beads, giving the necklace of 10x power and invincibility, so this time I was wondering how fast I could beat it (answer, around 15 hours, getting all the brushes, feeding anytime ‘feed’ showed up, digging up any nearby clovers and treasures but not worrying about searching for them, and doing any sidequests that were triggered, but not looking for any (did the first two monster hunts and one of the demon gates in spider caves), and spent more time than I should have being lost.
I do love this game, even though it is very easy (or maybe because it’s easy) and Issun is extremely annoying. I wish there was a way to turn off the Issun’s ‘helpful’ instructions; generally I know what I need to do but sometimes it takes a couple of tries to get the right brush stroke (in general, I can’t draw a straight line with a ruler; thankfully, this game is fairly good about accepting sloppy brush strokes). The art is gorgeous, and I am tempted by the artbook. The soundtrack fits the game perfectly, though I liked it better in the game than on its own.
The official site has more information and a few screenshots and wallpapers; I wonder if they’ll add more for the upcoming Wii version.