Really cool! You've got some very nice puzzle mechanics here, and you've done a really good job of gradually increasing the difficulty and complexity of the levels' designs.
I also really appreciated that all the controls were displayed in-game, in their relevant contexts. I noticed checkpoints were included early on too, which is a good idea for reducing possible frustration.
Great choice of music (even if it was pre-made). Charming choice of retro graphics, too.
I eventually got stuck on a level where I couldn't reach the red door at the top left, which seemed too high for me to jump to. I tried a few things, such as holding the jump key for longer, trying to climb the white chains as either white or a different colour, trying to wall-jump, testing whether the drops could jump higher when combined together as white, and seeing if I could split mid-air and then jump while still in mid-air, but I'm not sure what I needed to do.
Really nice work!