Very Nice
I like gladiator games, and flash games, so right off the bat I loved this game, a few things i noticed tho, was that the game was short (i read that its just a preview though), the game glitched here, there, almost everywhere, and there was no save(which i also read was in the works).
A few things that could be cool could be mini game sort of things, where you and a computer ally fight off lions, or hoards of something else, or maybe have magic attacks, or ranged, so you could focus on a class of some sort. Also, maybe have multi enemy situations where its like 1v2 or 1v1v1 so its more "arena" style. Just some thoughts.
Over all, great work, and you are definantly getting a 5 from me.