Hey, that's a nice little rhythm game !
I struggle a bit with level 3, when I realized I could just ignore the arrows coming from the top-right, and would have enough HP to survive. I tried to look at them, but the pace of the number in the bottom was too fast, and It made me lose too much HP... ^^'
I don't know if it's just me, but the rhythm seems to starts to deviate a little bit at a time, and I can feel a bit of delay the further into a level I am. I ended up following the rhythm of the spawning notes instead of the song.
Great job nonetheless !
Have a good one ! o/