[.sleep] is an experimental game/experience/exercise in sound, created over the course of a few hours of work (it was built using many assets from The Succession's prototype, lending to its quick development).
The original impulse behind creating the game arose from insomnia and the daily grind of unfulfilling work. I suppose it could be called a "falling asleep simulator," if you wanted to be cheeky about it.
I suggest that you play with headphones, since it is mainly an aural experience. I also suggest that you play using a gamepad, if available.
The Unity Web Player version has lower-quality audio; the downloads contain uncompressed .wav files.
NOTE: Don't fret, the black screen is not a bug. This was largely an exercise in sound and minimal gameplay/visual representation.