Hi there!
I've played for 10 minutes, here is my rating:
- Fun/Design: It's pretty fun at the start. I like the way there are multiple patterns of "bosses" during the playtime. The controls are responsive. In the other hand, after a few minutes I started to feel a bit annoyed: same patterns coming again - very easy to learn, difficulty being very low, didn't felt engaged enough to pursue the playthrough.
- Music/Sound: The music is calm and fits the gameplay well. Sound effects are also present giving enough feedback to the player.
- Graphics/Animation: Super minimalistic but overall coherent and enjoyable. Can't say much here as it's all cubes, triangles, lines and spheres but it's alright and the color change over time is looking cool.
- Theme/Limitation: I feel the game is lacking of a real "boss". I know you explained each "wave" is an actual boss, but I didn't feel it that challenging and epic. The "on the edge" is pretty clear here, as you're getting hit if you go out of the moving zone: on this note, I think speeding up the damages done to the "boss" the closer you get to the edge would have been a great addition!