Awesome game! One thing that I think could add some replayability, is if there was an effect that made the stick look like its a squeegee cleaning a window, so make the background a window and give the stick a cleaning effect, making its path shiny. This would A. be a cool and satisfying effect, and B. add the possibility of a game mode where you have to clean 100% of the map, or just certain "dirty" spots. Really fun game great work!
Just had another idea! you should make the music affected by the player movement and actions, similar to Ape Out, the Devolver Digital game. that game has a jazz soundtrack, and when you hit something or throw something the drums crash in and it makes you feel like your composing the music. I think this would be perfect for your game, as you could have a beautiful melody lightly playing when you're floating in the air, and have piano keys play when you hit a wall, so how you play determines how the music sounds. If you're able to gracefully soar through all the obstacles, the music will come out gracefully and smooth, but if you continuously are hitting walls the music will come out louder and faster, creating a sort of controlled chaos. Love the new levels btw!