Wow, this game is awesome. The atmosphere, the art and the sound design are incredible. The audio track is awesome aswell. The levels are very well build !
The only constructive feedback I can think of is that it would be nice to see where you are gonna impact with you sword. It's incredibly satisfying to do a double kill, but it is incredibly frustrating to miss it. If you don't want to make the emphasis on the detexterity of the player it would completely make sense to show the whole trajectory of the sword.
Maybe a key to restart immediatly would be nice too (your animation is gorgeous, I just saw it too many times).
Congratulations, you made something awesome.