A short small game with pleasant, not ear-splitting music, the same can be said about sound effects. The graphics are pleasing to the eye, it feels like everything really is drawn with a pencil, it looks natural! Passed all ten levels, in the beginning (1-5 levels) everything is quite simple, and then it becomes more difficult. The difficulty of the game levels is balanced, not too easy, but not difficult to break your head. It seems to me that the piano soundtrack is very suitable for this game! I can't imagine it with any other instrument, whether it's a wind instrument, a string instrument, or computer music. Good choice! In the menu, I would advise you to make separate music, or vice versa, because here and there the same thing is playing, it's a little boring. By the way, I'd like to have the exit button, for some reason people don't like to add it, as I see, they seem to always forget it.
[Bugs and other stuff]
When I was playing I found this thing with jumping animation, it annoys and makes a bit difficult to play. This can also includes sliding from the edges of the platform. 
Also, found this bug on last level.
Overall, good game, enjoyed playing it!
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Thank you for taking the time to play the game and leave such detailed feedback. I really appreciate it. I'm also very glad that you enjoyed it and went ahead and fixed many of the issues/bugs. I also added the much needed Quit button. I do have plans to increase the music selection as well as the overall quality of the game sometime down the road. Thank you for your feedback!