Finished Manifold Garden!
Took me five sessions, for a total of a bit over 5 hours. I did cheat by looking up a few puzzle solutions I got stuck on though. Very good game, although I think it could've been a little less vague. You're restoring natural elements to a world of infinitely looping architecture, but I'm not even sure if you're supposed to be playing a human (it's first person so you can't tell, and you never hear footsteps while moving). Birds and trees do exist, but that's about it for organic lifeforms.
The unexplainable nature of the world shouldn't be lost, but the game could use a more concrete reason to keep progressing beyond "I'd like to get out of this dreamlike environment". Good game though, quite hypnotizing and I found myself thinking on puzzle solutions while doing dishes and such, so it was often top-of-mind for me this week.