Too short, but otherwise AWESOME!!!
It took weeks to unlock most of the characters. Then came the credit challenges- Sharingan Sasuke and Orochimaru. It took the longest time to get the money, during which the game became duller and VERY repetitive. My advice- DON'T TRY TO GET THOSE TWO IN ONE SITTING!!!! Lol, it took the four of us a week, and after those endless Oboro mode matches, the game was new again.
We still whip out this game whenever Zelda: Twilight Princess and Final Fantasy: Crystal Chronicles get in the least frustrating. It's nice to pummel Orochimaru with Akamaru instead of throwing your TV and air conditioner out the 2nd story window. Trust me.
Also, if you want more story, I would recommend waiting for the next installment to come out. This one only goes up to just before Naruto and Gaara's battle.