Very cool concept, and mechanics. Lining up and hitting multiple enemies with one slash feels very satisfying. Even though the art isn't perfect I really like the tiled background.
The ninja has a limp alright ;( don't make fun of his walk.
Seriously though I will redo the animations as I was rushed for time on them and I had to do the programming as well. I think the art adds to the atmosphere of the game along with the post-processing and the UI.