The Stanley Parable
I was aware of the mod but for whatever reason didn't grab it, but now there's a n HD version on Steam. I really can't describe this game in ways that are able to sell it to someone without saying "well... I really liked it!" It is like
Dear Esther but then it's not. That game was more like a walking museum tour, and while
The Stanley Parable is the same, it's not as obvious. By that I mean you're more engaged with the narrator and the secrets of the experience that you're not thinking of it in the way of a museum.
Look, it's hilarious and really smart with a lot to say about video games and ideas of freedom. Basically it breaks down to this, did you enjoy
Portal? Yes? Then you'll enjoy this.