This was intriguing and engrossing. The back story sounded sad and enigmatic. I like the simplicity of the design combined with the rich environment.
The thing about pixel-hunting though, is that it can be frustrating and pull you out of the immersion. You sit there clicking nonstop on everything until you find the one thing that will react. This is particularly difficult with graphics that have neither color nor high contrast; as a result it can be difficult to distinguish certain objects, and I believe the hunt turned out harder than intended.