First a few nitpicks:
-The box falling feels a bit slow an awkward, the fact that it and enemies can move whilst in air also sometimes gives the feeling that things end up where you don't want them.
-Buttons really could have done with some kind of connector to show what triggers what, a colour or a symbol or a wire.
-Level 13 feels like I cheated (or so it says in my notes, sry I can't give me detail but I've forgotten honestly)
Those aside, this is quite a strong puzzle platformer. I really like how the mechanics evolve with the story. Nice art, nice music.
I don't really have any big complaints as such, just suggestions on how it could be taken further. The ability to rewind time would be super helpful, for when you've done part of a puzzle but mess up later and need to restart. I recognize how difficult that is so a savestate feature would also suffice.
Overall, as well made as the game is, there was a slight sense that it began to drag after a while. Perhaps puzzle games need an extra intensive, I think the gameplay can feel like work, which sounds bad but with reason to push forward this might be alright for the game. In something like portal this would be the story. Minecraft is one of the most work like games and yet it's fun because your working towards building something. I know this is vague, I just think that some extra drive might help the game from becoming dull.
Another way to help this might be to have more of a world. Making every level separated, boxed in with no real sense of a world around you probably isn't the best way to draw people in.
Again though, nothing I really have is a major complaint, more nitpicks. As a whole this is a really well made puzzle platformer.