For me, the game seems too easy.
There should be a moves count/ limited number of moves like in Candy Crush Saga or something like that. You don’t necessarily have to put rotate clockwise/counterclockwise controls and there should be a way to get back to some puzzles.
I found a solution for level 21 that doesn’t seem to work, but then I rotated the pieces for some reason and then got it to work in the same exact pattern I had. What a strange glitch
There are also seemingly multiple solutions for level 38, but the one that works is the four circles solution. Please refrain from multiple solutions puzzles like this unless any of them can get to the next level.
I finished level 50, and there is no end screen/game clear screen or a way to return to the title menu. Instead, it brings the player back to level 50.
Music is probably mandatory, as well as a music mute button/sound controls. There could be sound effects that you could add as well when rotating the pieces and finishing the puzzle.