How has no one mentioned Outer Wilds yet? That's usually right on up there in these kinds of threads, because it's great. An absolute masterpiece of a game.
Pathologic 2 is also a masterpiece, but a (purposefully) miserable game to play. It's so beautiful and the world is so rich, but it definitely demands perseverance to make it through, because it will do everything it can to make you hate it.
A Short Hike isn't quite as narratively satisfying as the other two, but it's short and fun and extremely adorable. Just a pleasant little world to spend an afternoon in.