The art and animation is obviously excellent. The feel is excellent too. Very nice work on those fronts.
With the controls, it feels like I'm fighting against my character a bit. When I hold left and attack, my expectation coming in was that I would attack to the left. Changing direction in general seems difficult for me. It feels a bit like fighting game rules. But in fighting games, you have one enemy who is always right in front of you. Here, I have guys all around me. This seems more like a beat-em-up, where you are mostly focused on crowd control.
It really wasn't clear when an enemy hit me, except that I died. I didn't quite feel like, "Ah that ninja got me". Rather, I just felt "I guess someone hit me with something, somewhere". Might be worthwhile to have enemy attacks more clearly broadcast, and only allow one or two to attack at a time. I think it's possible to have hectic crowd-combat, and also have clarity.
I want to come back to this one and explore the combat system in more depth, these were just my first impressions. Nice work.