Thanks for playing and for the thoughtful comment! I love how many people got attached to the thrall, its very cute.
I can't recall if I brought it up on a different thread, but I definitely see how having the doors kill the player/thrall in previous levels would teach the wrong lessons. I ended up putting in that kill mechanics since some of the levels were cheesable, but never got to playtest to see the effects fully. There is a weird glitch with the thrall turning to stone that lets you recover it through the right side passage, but that's definitely unintended and by the looks of it, I don't think anyone found it (yet).
I'm glad you enjoyed the puzzles regardless, hopefully I can get more puzzles put together post jam.