I came here to leave a comment and then realized that Huckleberry already said nearly everything I was going to mention (especially the praise and compliments about the crazy cool mechanics and overall polish). . . so instead I'll just second his points, and then add a small idea of my own to (maybe) make combat more fun / engaging:
Maybe have enemies come in "schools" or differently patterned groups? I don't know if the waves are pre-determined or just random, but they definitely feel kind of randomly thrown together and create a lot of visual clutter / noise / a sense of aimlessness during combat. I feel like maybe introducing the player to different enemy patterns over time could help them to feel more purposeful and fulfilled as they learn to master the combat. There are lots of great enemy types already present, maybe certain enemy types could even work together to form different attack patterns instead of all just doing their own thing?
Anyways, the team did an absolutely fantastic job with this, and I look forward to seeing how this is updated moving forward!