On the surface it has very little but it'll keep you playing
On the plus side the character models are very well done with all the characters looking recognisable and have good voice acting. At some points the voices can be annoying, like Sakura shouting "Is that all you got" before the match has even started!
There is a large selection of characters from the old crew Naruto, Sasuke and Kakashi to more obscure characters like Mizuki, the villain from the first episode and Akamaru ,Kiba's pet dog. Each character is unique and aimed at people with very different fighting styles. My personal best character is Neji because he has strong and fast attacks and a very effective special attack, the 8 Triagrams 64 palms.
Each character has a different colour scheme or outfit; some characters like Sakura and Haku have 4 different outfits as you can get Haku with and without his mask and Sakura with long and short hair as well as different outfits.
In conclusion this game is quite limited as all the modes are similar and the story mode is awful but the large amount of characters and the large amount of un-lockable's will keep you playing for a while and a hardcore fan should certainly add this game to their list. Rise of a ninja is generally better but Clash of a ninja 2 is a very good effort.