Question for the developer, have you played the Playstation video game Journey?

The spoiler about it is, that while you adventure from one end of the land to another, and you encounter other sort of people looking players, it turns out that those are actually people and, at the end of the game you get a credits roll list with the PlayStation Network handles for each of the players that you encountered. There is no communication other than moving your character. It's delightful.

Anyhow, that subtle engagement is in my opinion quite valuable.