Above my expectations. Nice game. It is actually a 'programming' game under the hood if you think about it, and there were some fun levels.
One frustration I had was when you are stepping through the bar you cannot edit the notes, but it does not have any visual feedback, so sometimes I was clicking without being able to edit anything, to then realize I was in 'stepping mode'. So a small usability issue that could be improved. Maybe make the nodes greyed out or something would be enough.
The way the camera works, you always have to fail some times to get it right. As you cannot see what is to come, there were some levels that I just pressed forward some times to see what would happen next. Was thinking about it, maybe a nice feature would be to allow the player to pan the camera forward when there aren't any notes on the track, this way the player can hit play and inspect all the level and study how things move before starting to work on the solution.
Really nice game, congratulations on the project!
I also made a music game. It is more a rhythm game actually, but uses the concept of a looped bar of a music too! It is a tower defense with rhythmic inputs. You might like it :)