The basis of the game is there, and I can see it being pretty fun; 1v1 duels against a number of bosses. I think being able to earn money or experience to trade for upgrades could be fun. Perhaps having a number of different play-styles as well, relying on more/less mobility and whatnot. Having more geometry in the arena would be nice, as well.
Overall, if you keep at it, I'm sure you could make something cool out of this.