Finished it late last night. Despite the hour, i was wide awake for another hour after the ending.
What a chillingly brilliant game.
Tracked down a interesting easter egg(doesnt really fit that description, but close enough). Do not look if you havent beaten the game.
SpoilerAround the 14 second mark, crank up the volume and listen closely.
Crazy amount of foresight on Levine's part.