Where to begin, the music is a bop.
I'd recommend looking into the audio sliders a bit more, you need to do some funky math to get a 50% slider to be 50% volume. I feel feedback when the player is hit is needed, maybe something like slow the game speed down to 0.8 and a little red on the sides for a moment.
I found myself just running in a big circle. which makes me think that the xp orb system in other games is there to prevent that, pushes the players to pull the mobs away from their loot and makes risky situations where you want to dash in to grab that last bit of xp.
Eliminated enemies seem to linger too long and blend in with active ones, I'd suggest either having them vanish sooner or having them turn black to help distinguish.
Finally, I'd add a time/score thing. something to make that monkey brain numbers go up feeling.
Best of luck with the game!