I'm looking for a similar (calm) game like Portal 1/2 or Firewatch that I can play on macOS with a similar vibe. The last time I played a game is years ago, and I wish I had at least once a week a nice single-player game that I can play 1-2 hours. =)
I enjoyed Portal because I had to plan out what I'm doing before I act (without being pressured to act), the atmosphere of the game was legendary and I liked that little robot following me. Firewatch had a calm amazing story, there was no 'action' but sometimes that feeling that something could happen. It was a nice exploring game.
Exploration focused games that are pretty calm (for the most part). They are some of my personal favorites. I recommend not looking up much about them (especially Outer Wilds and Tunic. Learning mechanics from gameplay is part of the game for those two). Tunic is probably the most action oriented of the lot, (like old Zelda games) and it leans hard on the puzzle aspect, so if that's not your favorite then it might not be for you.