It's a not a bad game, but not a good one neather.
The biggest and greatest thing about the game is the online multiplayer, because it tracks and records all your online stats giving it soem compelling online action. The single-player mode while not bad, it just feels abit repetative towards halfway. And unless you have already seen the anime the story is abit confusing.
Graphicly the game is sound. The environments look really nice, with some decent lighting effects all around. However the characters don't seem all that good. The lip sync is off and some cases the lips don't even move when the character speaks. The voicework is what you would expect.
As a fan of the english dub here i can say the voice actors do there job well enough for it to be good.
Gameplay is a mix bag. The action and fighting is fun, but all the borring side quests and story missions drag on too much. And you will find your self doing the same stuff over and over.
Anyway decent game if your a Naruto fan but not a great one at the same time.