Nice work! It reminds me of "Bloodthief"
The sfx and movement was satisfying.
I got a freeze on firefox while fighting the boss (I attacked a minion near him, maybe it hit his hurtbox when he was supposed to be invulnerable?):

Good entry!
Sorry about the freezing. I think I've figured out what the issue is. It looks like you have a large screen resolution based on the screenshot you sent through. The enemies only spawn in the arena outside of the player's view, but if the player's view is larger than the spawn area, it would get stuck in an infinite loop, causing the freezing. If you exit full-screen and make your browser smaller, it should stop freezing, hopefully.
Thanks for the kind feedback.