good job! the puzzles are good, and the mechanics are executed well. as others have pointed out, I think the most critical things to polish are probably (1) making the mirror worlds easier to distinguish and (2) cleaning up the touchy spike collision readability (it's a little unclear to the player where the spikes are triggered in relationship to the player model).
(1) is kind of interesting because, looking at your cover image, it's clear you had a valuable insight about this already. picking a color and its complement (orange, teal) is a great way to visually distinguish what the player sees. try something along those lines? or perhaps make buttons different colors on different sides of the mirror -- the buttons were the thing that confused me the most.
for (2), I would maybe just try a different player model altogether. I don't know what your vision is for the look of the game so I can't say much here, but something with clearly defined boundaries would probably help. zarvot is a random game that comes to mind.
good work!