Good, but loses its quality after extended play.
Quality is apparent here, especially in comparison to the previous "Ultimate Ninja" installments. Lets go down the list.
GRAPHICS--9.0. From the manga-esque appearance of the character models to the chakra and jutsu effects, this game is beautiful. What keeps the score from going any higher is how lifeless Konoha feels in "Ultimate Contest" mode.
SOUND--8.0. The jutsus and voice acting--both English and Japanese, respectfully--are pretty high up there and match the quality of the show, but you'll probably want to have the Japanese voice overs on. The English voice actors can get...pretty annoying after a while.
PLAYABILITY--7.5. Pick up and play controls are awesome when all you want to do is pound someone's face in, but lack of any real depth makes playing this for any longer than an hour after the initial six hours of enjoyment a hazardous idea.
Entertainment Value--8.5. The first six hours of the game are an absolutely awesome experience. After that, you shouldn't play it for any longer than an hour at a time, or you'll tire of the game quickly.
REPLAY VALUE--HIGH. Despite everything I've said, you'll be popping this game in a while after you beat it. Its just that fun.
OVERALL--8.0.
You'll have a good time with this game. Just don't force it to overstay its welcome.