Eidolon looks fantastic, and it sound like it will be really fun to play. It's set in a "post-human Western Washington", and it's a game that revolves around exploration. The developer's website sets up the game like this:
"You will be dropped into the dreary and mystical Western Washington circa 2400 c.e. with a bow, fishing rod, and little to guide your way. Awaiting you is a vast landscape filled with wildlife, edible plants, and the historical artefacts of our now-dead culture—journals, newspapers, zines, brochures, transcripts, and more. You must spend your fleeting moments moving through this place, collecting what was left behind, and piecing together what happened to these people, both from a historical perspective and from a much more personal one."
Eidolon will be out sometime next year for the PC and Mac, and it's on Steam Greenlight right now. It looks great, and I will definitely be paying attention to it.