Audio is a hack made by Pyrojay for the Music Themed Level Competition, in which it officially placed 42nd but has been tagged as placing last. There is no gameplay, just an image that fades in and out.
The many-worlds interpretation implies that there are very many universes, perhaps infinitely many. It is one of many multiverse hypotheses in physics and philosophy. MWI views time as a many-branched tree, wherein every possible quantum outcome is realized.