I remember seeing an interview with Omar (I think it was either the G4tv one or the gamespot one, don't quite remember) for this game's E3 showing. The interviewer asked him about the SSB similaries to PSABR. He admitted that there are similarities and that some of the gameplay has been inspired by it. So I don't think SuperBot is completely denying that their game has taken mechanics from SSB.
On the matter of anime reps, if anime reps would make it in the roster, then I think should visual novel characters should be in instead. Visual novels are techinically video games (albiet not very interactive video games) and so their characters will at least have more video game roots than anime characters since the characters originated from video games. While highly unlikekly that they will be inlcuded in the roster, it would be cool to see Emiya Shirou (Fate Stay Night) or Tohno Shiki (Tsukihime) fight off against the likes of Kratos or Cole.