The quintessential philosophical puzzle adventure. For once, the gameplay has made a proper connection to the narrative, in a way that could rival Portal. It is very on-the-nose, but actually supported by its setting for once. And the puzzle-to-story ratio is also good - there's the obvious final indie game choice though. While it came out later than I remembered, I think it is a very good template for puzzle adventures - just the right balance and nothing overly flashy, standing right between involved non-standard adventures like Outer Wilds and very rigid games like most of The Talos Principle.