Very smart! I love that the healing rooms are one-way entries, forcing the player to plan their map around it. IMO, there should've been fewer rooms overall, so players would need to use all of their pieces in the final stretch. I never saw some of the hardest rooms because I didn't need to use them. But I loved this!
If you're going to expand on this game in the future, having certain areas have 'hazards' that effect the room tile placed there among other spatial puzzles (like rooms that can rotate with levers) could be really interesting. I think there's still a lot of potential here!