Very cute game. I like the controls fine as is, but customizable binds would be nice for sure. The duality between worlds was really effective. Using the black objects and backgrounds for both realities was a great way to add a bit of a spooky vibe. Even I wasn't alone, I sure felt as though I was.
One interesting thing I noticed was that during the falling animations of blocks, I could perspective shift and the blocks would still be suspended in mid-air. I'm not sure if that was intentional, but it could make for some pretty great puzzles later on.
My biggest gripe is the lack of music. Even a simple ambient track could add a lot. Also, perhaps a button could be added which pulls blocks rather than pushing them.