I love the puzzles, you got a pretty nice tutorial and pretty challenging puzzles, got me hooked till the end, I love it! I do think sometimes it gets a little too much, it's pretty hard juggling all the colors together, like a Rubik's cube where you finish some part and get scared of messing it up while you try to get the rest in place, but as a whole the levels allowed you some experimentation without horrible consequences, sometimes you could just walk around without thinking too much about what you were doing and then you'll figure it out.
I also really love the graphics, you turned additive blending into gameplay which gave you a nice excuse to mess around with shaders! That overlay on top of the chonky pixels looked cool, let you differentiate from the typical pixel art games and allowed you to mess around with color animations and pixel movement without having them break the pixel aesthetic too much, pretty smooth! Sound effects were also cool, fit the pixel/old monitor aesthetic very well. I just kinda missed music, I think it was the only ingredient to top of a great cake.
But yeah, definitely one of the my favorite games so far, great job!