I love the concept art and the character work. I... am somewhat bothered by the backgrounds still.
Still lots of experimentation going on.
Not sure what you mean by "a generic texture filter," though, because all the new textures are hand-painted.
Also, keep in mind that it looks very flat now because those only have ambient lighting applied and no shadows. The prototype's backgrounds had shadows painted in with vertex lighting, which is part of the reason they looked so much more "3D."
I'd also like a little info on how you're trying to make the backgrounds look 2D.
We're still experimenting, but the environments will be a mixture of 3D objects, 2D textures on bent surfaces to give them some depth, and 2D cards. Basically, the further back you go, the more 2D things become. And things in the foreground, like obstructing columns, plants, etc. will also be 2D.
We're trying to achieve the "deep painting" look we had with Skullgirls environments and the set pieces in the prototype, but hitting that with modular geometry is a lot harder than dealing with custom pieces.