Really cool concept. Judging by the billboard for the full version in the arena the game places you in, this is a demo of the battle engine.
That said, the camera controls are a bit wonky. I'm not so much a fan of having to use a third joystick to control the camera angle. Especially when I could be using that thumb to kill things. Also, I'm not a huge fan of the main character having only two or three battle animations. Not much fun to look at.
Despite all of this, I kinda like the idea. The graphics look good, frame rate is okay on my 4S, and if the full version is any improvement upon this, you've got yourself a solid hack 'n slash. Good work. :)