Yeah, I'm loving it so far. I have been disappointed by a couple of games which attempted this genre (your "7th Guest"s and your "Myst"s) but just didn't have the gumption to give more challenge than just wandering around and going through some sort of trivial semi-puzzle. Blue Prince seems like it strikes a really good balance between dropping hints so you're not totally lost, and giving a sense of progression so people don't get discouraged, but also not being afraid to give a meaty challenge.