A very interesting puzzle game. I have a few observations:
1. There is no mention anywhere that the 'R' key is reset. It would definitely be useful to add that to the intro screen.
2. In the final puzzle I don't use any of the objects to escape. I only interact with one box to get it out of the way, otherwise it's a case of walk/fall to the exit. Was that not the intended solution? Or are there multiple ways to solve some levels?