I do level design in Source Engine as a hobby. I enjoy trying to make Source not look like Source, if you know what I mean.
Stories of lost souls of children who followed the dancing wisps deep to the core of the Darkwoods, to the Heartwood. Now they too, like the trees and stones, are now apart of the forest. The eyes and ears for... it.
That makes me think about those indie thought-provoking games.
Let's say :
The environment is randomly generated, beautiful scenes everywhere, NPCs that predict flight paths by their own nodes.
You can walk around everywhere but there is one catch...
You leave a trail of darkness behind your footsteps, and you cannot re-enter that area.
So each time you go somewhere, it will be only once.
Think about it like "Appreciate the moment you are in, for it may be the last one of it's kind" type of game.