Cool game! I like the graphics, very minimalistic but they work well. The core gameplay loop seems fun!
Some thoughts I had while playing:
It took me a while to understand it works, since I didn’t realize at first that your health was your mana, and that there were pickups to restore it. Maybe you can explain this with a quick popup before the game starts?
I felt that the upgrades you would get were not strong enough to keep up with the increase in difficulty. I ended up dying early most rounds.
The character feels way too slow for me, sometimes it feels impossible to dodge things.
The game would really benefit from some sound effects as well.
Overall, this is a good start and I think this can become a really fun game!