So going into this game, I figured it wouldn't be smart to treat it like it was Super Smash Bros. with Sony characters and that was a good idea. This game doesn't even feel the same, despite looking like the same concept. Something seems a little bit off. To compare it to Super Smash Bros. just feels unfair, so I will treat it like a standalone fighting game.
This is a pretty basic concept. Fight till you get enough energy in a bar to use a special to win. Simple concept but each character has different specials. Many of them range from screen clearing attacks to easily dodged attacks that are annoying to use. That's the key to any fighting game is balance. That's what this game lacks.
They did recently patch the game to fix the fact that Sackboy was near impossible to hit but as of this post Kratos is still overpowered and Raiden has an attack that is easy to get off and clears all those around him. Unfair, not really because both those things are only issues for new players. But it does get annoying to jump into a fight and get bombarded by the same three characters.
One not I have about this game especially, over it's PS3 brethren. The mic feature is stupid. It picks up too much sound and there is nothing in the game manual on how to disable it. Yes, it has to be disabled through a Vita menu but it doesn't mean you can't have a blurb about it in the game manual. When players have to use Google to figure it out, you have problems. I would say this game is skippable, unless you are looking for more games for your Vita.