I simplified songs 1 and 2 just recently so ideally they should be easier to play if you'd like to try again :) Song 3 will still be hard though.
Regarding feedback, I agree alot! The original plan was to include a hit sound effect when you hit the note correctly, but unfortunately the web audio didnt sync that sound effect correctly (it consistently lagged) and threw off the rhythm every time. It kinda works on windows, but there's some variance that's grating to the ear sadly. I'll try and see if I get any luck fixing this issue, but still glad you enjoyed your time playing the game!