That's "hidden gem" rather than "underrated."

But I agree with others that are saying it's just niche. It's a pure puzzle game. There's no exploration, crafting, combat, survival, etc. You have to really like puzzles to play a pure puzzle game.

I do, and I've still been struggling to make it all the way through. I'm just starting on the last of the first 12 sections, and some of them have kind of been a slog rather than a joy.

I can't even give any particular complaint, though. Each puzzle really is different from the others, so they aren't duplicated in any way that was obvious to me. It's just a lot, I guess.