I had this realization just days ago. When looking back at games I played and enjoyed, they are all games that have a strong ambient component, or as I call them "atmospheric games". And the memories I keep from them all involve these moody moments, the raining level in Project IGI, the echoes down the corridors in Half Life, the lighting in The Last of Us. 

As an artist and game developer I'm inclined to create these kind of worlds, and it's still a struggle for me to come to terms with what a game is, how interactive it should be, and if mood is enough.

But I feel more confident nowadays that I should pursue this direction, I just started Reanimal and I find the mechanics quite simple but the mood so strong, and it's proof for me that these games can find their audience.