I don't know why this has so much effort put into it but it's pretty cool I can't lie. I'm not huge on doing JUST the combat part of persona and maybe it would have been cool to see an attempt on a full conversion of SRB2 into a persona game, but if you have friends who like sonic and persona then this is a pretty fun game to play for a bit. Setting up the online was not fun however I hate port forwarding.
It's Persona 3 with Sonic characters and online play. It's a fun game to play with friends, especially in a genre that's sorely lacking non-mmo co-op play. Most of the balancing issues are prevalent in Persona 3 itself (Debuffs and physical attacks being overpowered) so I don't feel the game can be blamed for that. Single player content is just the online play but you control every character. Story content is gonna be added in an update and it's still very actively in development, but right now it's not worth the download if you can't gather a party. If you can, it's a great time.