This is a really cool concept, good take on the jam's theme! I'm pretty sure it's just my computer but it played at a really weird resolution so I couldn't see half of the screen unfortunately. You've got some simple but cool graphics, and I'm also impressed that you managed to get a combo system going. These physics feel great to play with, and you had some great work with the visual effects, like the post processing and particles.
Something I would suggest is making the game over screen happen a bit faster; when my thing died, I thought I got softlocked for a second because nothing was happening. It would also be beneficial to increase the arena size, as moving around felt a bit cramped and the controls more restrained. Some different enemy types would add to the gameplay as well.
Overall I really like this concept, you got some good things going here. Like what thmz said, I think this would be really cool as a mobile game. Good luck for the rest of the jam!