A lonely shore of a sea of forgotten memories. The viewer walks along it and sees artifacts in the water.
Pulling a net out of the water brings up an artifact caught in it. As it comes closer it dissolves into a cloud of particles and leads the viewer through the story: trees and houses appear, and a figure takes shape and tells part of it. The voice and the scene move only while the viewer pulls; when they stop, everything stops.
The full sample walkthrough, the world and the core mechanic are in the design brief (PDF, excerpt).