After having beaten the game, I just saw that you have put the solutions in your descriptions. Hopefully I didn't read them before playing because I like to know how I can get out myself.
The game wasn't hard, the puzzles were interesting.
I felt a bit creeped sometimes with the monocrhome levels, no sounds, and all alone. I was thinking that was going to be a monster out of nowhere (which is the ghost) but it didn't really do anything so the creep became just "puzzle-reflexion" at some point.
I think there is potential to expand the game into something more enjoyable. I liked going through it and I didn't think at each level "when this is going to end?" I enjoyed the new challenges even though the last level I had to do it 3 times over to understand that the exits were fake.
It's a good realisation and I wish to see more.