The emptiness you feel inside yourself when you complete the main storyline/campaign of a magnificent game (such as The Last of Us, any of the Uncharted installments and The Walking Dead game by Telltale) and have a brief period of depression where you seem to have no reason to move on with your life.
James: Hey Joe, how was that new game by Naughty Dog?
Joe: Oh, The Last of Us? It was amazing. When the credits started rolling, I went through post video game depression for a short while.
James: I bet. Had the same feeling with Mass Effect 3.