As others have mentioned, I had a lot of issues with the animation syncing. Eventually I realized the game was a lot easier if I actively ignored the top half and only watched the arrow line, which makes it playable, but kind of ruins the effect you were going for I imagine.
The gradual ramp up in speed was really unexpected, but felt pretty fair. I kept expecting to just die eventually but you got me to do the "flow state" thing indies always moon over and I just ended up knuckling under until the end. Made it out with 413 and all my hearts but half of one! I'm weirdly proud of that. Which I think says something about the inherent compelling nature of your game, flaws and all.
I hope you keep making more stuff in the future. Not all of the games are inherently engaging - their devs have to make them that way. And I think you did with this one.