Great concept and great design! The mechanic is very simple but the way you made it work makes it fun and interesting to use. The levels get progressively harder (with a balanced difficulty curve - in my opinion) which made the learning process interesting but challenging at the same time. The aesthetic is nice and the sound effects fit.
The only thing I did not understand are those symbols you placed on top of the levels. I guess that those are meant to help you get through the game? But I did not get how.
One last thing. This felt good to play, you could consider expanding and making it into the mobile market? It feels like one of those games that you could play while on the train for example, like Color Switch, check it out: https://play.google.com/store/apps/details?id=com.colorswitch.switch2&hl=en&gl=U...
Congratulations, I liked this a lot!! Keep developing! :)