The camera perspective doesn't make a difference to the genre, it might merely create a sub-genre at most.
What defines is a fighter is:
-Are there multiple attack functions and options for the character?
-Is the game designed with a PvP focus of some sort?
-Is there some kind of system whereby you can combo your opponent without them being able to escape?
-Are certain options designed to trump other options in a rock-paper-scissors fashion? (e.g. Shield beats Attack, Grab beats Shield, Attack beats Grab)
These are pretty much the only 4 elements that are a necessity for a fighting game.
Granted, I'm still not quite sure Punch-Out and Wii Sports count, I'd have to play them again.
--------
Also I agree with
wedl!!
that UCT should not be legal, no more than a counterpick anyway.
My main reasoning is that some of the platforms that fly in are actually solid from all sides (unlike Smashville where the platforms are "thin platforms" that are passed through from the bottom and sides, and you can drop through the top), meaning you could have a good combo going, maybe something focused on knocking the opponent of the top of the screen, and all of a sudden, one of these platforms swoops in and your opponent can tech and punish you, or they may even just rebound off it and use that to get below you and now they have the upper hand despite you being the one to send them into the air. It's a bit dumb.