wow this is hard as hell and I am not so good with motor reflex stuff.
One thing that is interesting here, just like hard games like celeste (in this case I see it more like a Thumper, horror rhythm type of thing) is that after a while you see yourself memorizing the sequence and the timing so it gets less scary.
I can see this being a very addictive loop, the game core has lots of potential for that, I can imagine this with a frenetic soundscape and you have a strong potentially addictive touch experience (Thumper with one finger would not be a bad thing).