Maybe I'm biased, but having also made a puzzle based on the same movement mechanic, I found it so cool to see the direction you went with it! Goes without saying that the levels were really compelling, but maybe an undo and/or reset button would let the player explore and enjoy them more fully? I think I felt too focused on not messing up/running out of time that I couldn't fully appreciate the care you'd put into them.
Oh, and I for one thought the irregular die was a nice touch; made me think *that* bit more!