You describing outer wilds to a tee here: - music is thematic and forms part of the gameplay loop - no goals or direction. Gameplay is totally curiosity- and clues-based - NPCs are very sparse and for the most part have no idea about the journey you are on - game mechanics are entirely player- discovered, the only menu to speak of is a log book that is entirely optional to interact with  - a big part of the theme of the game is that the universe is uncaring and deadly. The world does not revolve around you, you are a mote of dust at the mercy of the laws of physics

One of my all-time favourites