Wow, this is awesome! I thought the idea was amazing, and I had a really fun time playing it. The music really pushed you to try to get to the next disc, and the tension of the game built up really successfully as you got further.
My only comment is about the movement. I really wanted to get further in the game but had a hard time getting the hang of the controls, which left me feeling like I couldn't improve. My issue isn't that the game was difficult, but that I felt like I didn't have enough control over whether I got hit. The delay after pressing a key was frustrating because it made it difficult to jump out of the way of nearby bullets, but at the same time, the character moved so fast that I couldn't evade things successfully if I always stayed in motion. It's also possible that it was just my computer (I'm on a recent-ish Mac). It looks like many other people enjoyed the difficulty, so obviously this is just my opinion. For me personally, I think I would've enjoyed it more if the controls were tighter, making it easier and more satisfying to avoid things, particularly in the earlier stages of the game. Then, the difficulty can ramp up as much as you want, as long as the player feels that they genuinely can improve at the game and learn to progress further. A good example of this is Enter the Gungeon, which gives you extremely precise control of how you dodge bullets, then ramps things up until you die. No matter how tough things get, you never lose the feeling that, if you just reacted a little quicker, if you could just keep your focus up a little longer, you would win.
Overall, I think this is a really fantastic entry, and that if you manage to find that sweet spot with the movement, it'll be an incredible game. Amazing work!