If you were more of a gamer person I would suggest you to make a Steam Group, that way you could play and interact more with your watchers
Here go some ideas/opinions:
Firewatch is indeed a nice game, somewhat slow paced, chilling game with awesome visuals. Shame it is so small.
If you like puzzle/mistery games, Machinarium might be pleasing as well, and being a 2D game, runs on almost anything (Linux included).
Braid is a nice platformer that is praised by many people. A bit more action based though, has a nice story to it.
FEZ has some unique visuals, it is a nice platformer with a nice story to it. It has LOTS of secrets to it, though if you are not a math/logic inclined person there are some puzzles that will frustrate you.
As for pure puzzle Cogs is one of my favorites... though if you don't like the idea of solving a Rubik's cube (the game doesn't make you solve one, but the challenges get harder and harder) you might want to pass this one...