This has some cool concepts and the general controls feel really satisfying, but it just feels too janky in its current state.
One big issue I had with just general controls is that the player seemed to bounce of walls in a really inconsistent way - sometimes they'd get launched backwards if I ran into a wall, other times they'd just walk up to it normally. It didn't feel like it was based on the player's speed or anything intuitive like that, and with how many small steps there were throughout the level that you constantly run into it was extremely easy to get messed up by these random bounces and made just getting around empty parts of the level feel more frustrating than any of the actual platforming.
Other big issue is the near complete lack of feedback when getting hit. No sound, no knockback, just a brief red flash that's easy to miss. I regularly wouldn't even notice I was at low health until I was teleported back to my spawnpoint at what felt like random.
The idea of using the combo system to gate doors seems really cool but since all blocks and enemies respawn as soon as they're off screen right now it feels like the best way to get past those doors is to just move back and forth breaking the same blocks over and over again which isn't a very satisfying gameplay loop. There was one section that seemed to be designed with a more active and specific combo in mind and wasn't able to be easily cheesed but with the finnicky movement I wasn't able to actually keep up the combo for the entire stretch and never got past that gate.