If you fall asleep while stargazing, a gate to a new world situated in between the world of memories and the world of dreams will open for you. That intermediate world gradually turns reality to fragments and infuses the player with the desire to know the unknowable. But the most persistent can feel the unknowable. The basic element of gameplay is the ability to forget. Some elements in the surroundings change when the player turns away or leaves, and become more than just a direction sign: they become the way along which the player walks, flies and falls. Finding such a way to the higher levels is a matter of his aptness and intuition, rewarded by advancing higher.