I like the idea a lot; I was not too fond of the way you have to play, lol.
You have to move around the screen frantically, and I wanted to spin the sword around constantly to do damage, but I couldn't even swing it at all while moving. It's too much to manage at once; I would prefer it with a click-to-attack or some other mechanism.
I think it has a lot of potential with some playtesting and tweaking, though; great job!