What a great, inspired idea! It was nice reading your description and seeing how the idea came about plus the tools you used to make it happen, but even without that I could tell from the game itself that this project was something you're really passionate about. I had a few runs where I scored 0 and I just couldn't get to grips with it. Then once I landed that first kill... and the second... and the third... It really hooks you in! I ended up chasing that combo and trying to time my slashes. It's funny as soon as you miss one or two when you start panicking and flailing around hoping to restart your combo again. Considering the amount of work involved in making all the aspects of this that you did, I'd say this is a brilliant entry to the jam and a game you should be very proud of.
Excellent submission, I can see myself coming back to play this from time to time just to try to beat my score!