Conceptually, I've seen very similar games before. Mechanically, it's a bit unforgiving for me. I stopped playing after level three when it introduced both mechanics at once. I gave it my best, but after failing 4 or 5 times in a row, I lost interest.
I was immediately put off by getting quite a long way into the first level, then failing and it sending me right back to the start. I know none of the levels are especially long, but when you have over 6000 other games competing for your players' attention, you have to be very careful with people's time.
I would have been more encouraged to battle on if I had some kind of indication of how much further I had to survive to finish the level. Level one felt really long. Level 2 seemed about half the size, which was a bit weird. I personally like to leave the early levels until later in the development when I know much more about what the game will actually be. Once I know that, I can carefully tune the onboarding levels more appropriately. I fully acknowledge that's not easy to apply in a games jam's tightly limited resources environment.
Getting the difficulty right is always going to be a knife-edge challenge in games like this. My old-man reflexes can't cope, but other people might find it trivial. There's never going to be a way to keep everyone playing without some new features like (say) dynamically adjusting the difficulty. I'm not really sure how that would work here anyway!
It's beautifully presented, both graphically and the audio. And it fits the theme pretty well too. Congrats on getting a finished game out in 48 hours!