Why make this a game?
While the background music is okay and could be considered relaxing, the gameplay was horrible, and there were some inconsistencies in the atmosphere for the game.
My gripes:
1) I have to hold down the right arrow key the entire game. If I release it for but a moment, I lose all of my precious birds, or I'm releasing it because I messed up (and thus have already lost my birds). In either case, I would be better served by some sort of auto-walk behavior.
2) The game is too slow pace. I understand that it is a game with a walking character and is supposed to be relaxing, but the speed was slow to the point of being annoying to me.
3) Why is there a score system in a relaxing game? So that I can compete with my friends on who can be the most chill?
4) Rewinding felt out of place. The nice and relaxing game keeps a full record of your path through the level? Why? Nothing ends up being done about the path. I don't get special music made based on my path. I end up having the expectation that it matters, but it doesn't.
5) Sometimes I can hit/graze an object long enough that my birds fly away, but I'm still able to jump perfectly fine and do not need to rewind.
6) There is no need to collect the notes besides score. They don't even make noise or contribute to the music (or I guess the music contributes to them, since it will suggest that you jump to get the note sometimes).