JW and Robin's art game The Gutter is an experimental piece of art that is free to play, but by sending in a five dollar donation to the developers you can download the full version which comes with one additional feature. The story is about a man who wanders the streets at night, not knowing the fate that would befall him further down the path he chose to take.

This particular journey won't take longer than a couple of minutes to complete at most. (source)

Also: The Eggyard