I can't think of a better example of what a 3D beat 'em up, with the aesthetics and themes of some of the first titles of the genre but adapted to modern audiences, should be.
Is evident that has influences from games like "Nekketsu Kōha Kunio-kun"/"Renegade", "River City Ransom", "Double Dragon" or more recently the "kenka Bancho" game series (in fact the developers of this last games are the same, Bullets).
It is also, in my opinion, a tribute to all those mangas and animes based on highschoolers, which happened to be delinquents, that lived only to beat the hell out of each other in order to gain a certain status as the bancho of each school or get the attention of the girls; such as "Crows", "Shonan Junai Gumi", "Be-bop Highschool", "Rokudenashi Blues" or "GTO".
It's fun to play, easy to master and has a colorful style that will leave no one indifferent. The art and design of the characters comes from the great Hiroaki Hashimoto, which most of you may know from the SNK series: King of Fighters.
The music by the way is awesome, having some rock 'n roll tracks and the main song made by Knock Out Monkeys.
Many critics comes from the fact that it's a little ecchi but, as I see it, is never offensive and makes sense given the influence of the mentioned multimedia franchises. Most of these stories used to had teenagers as protagonists with the goal of becoming popular among cute girls (besides is understandable coming from the creator of Senran Kagura, Kenichiro Takaki).
In my opinion is a must-play of the PS VITA catalog and a solid exponent of the 3D brawlers that every fan should give it a try.