First off, the engine needs some serious work. Slicing a sword towards a wall shouldn't push you back. In relation, the collision is totally wonky - many times have I got stuck in the ground or in a wall. The collision itself is awfully crappy.
Second off... look at Zero. He has this huge saber compared to the other character's little smacks. Some of his Special Moves are glitchy - with his Hyouretsuzan, I often fell beneath the floor - eh. This applies to all the characters in general. This argument also kinda works as how the sprite/art styles and such seem to collide too much. Beyond that, it just looks like everything is lazily stolen in the graphics department, at least for majority of the sprites.
Thirdly, sound problems. It seems that music sometimes leads into the next frame instead of stopping - and 2 music files seem to start playing at once.
Still looks promising, though, although how anyone giving this a 10/10 or even a 7/10 so far while being sane is beyond me. Also, this *is* a beta... :p
Gah, add Gardevoir or something. :(