This is one of those games that my mind drifts back to repeatedly. At its core it's "just" a puzzle game. But something about the worlds they're set in gives the game a weighty and sardonic sense of place. It's solitary, lonely, forgotton, and yet majestic in its decay.

Back to the game play, like most good puzzle games, there's a basic vocabulary of pieces that you employ to solve your predicaments. You start off simple, and more pieces and complexity are added as you go along. A couple puzzles are nigh impossible unless you happen to "get it", and there are a LOT of hidden easter eggs. But the pysicality of the puzzles make it really interesting, and the backstory helps weave it all together. Also, visually it's beautiful.

(Thematically, It's also a great companion piece to SOMA)