I like the concept of your game. Levels are challenging and keep the player wanting to play.
If I were to talk about the art , it deserves a 5 - star from my side. The sound and graphics fit in with each other perfectly.
I suggest working a bit on the start menu. Maybe, you can add a separate button for viewing the controls. Also, see if you can make a separate scenario for the background of the start menu. Last of all, try to add some scene transitions like fade in and fade out effects.
I hope the feedback helps you to improve the game.