Wow, this puzzle took me days, attempting, hitting surprising dead ends, unwrapping, resetting, etc. It wasn't so much difficult, as foreign from my comfortable genres (sokoban-likes etc). I had to learn new ways of seeing state and develop a novel set of strategies for pursuing and tracking intermediate progress.
Once I understood the visual language, the solution came fairly easily, and left me wanting more in the same genre. Has anyone played with creating variants?