Video Game Ending Syndrome is the intense feeling of sadness that a person may experience upon completion of a video game that the person was able to really immerse themselves in. These video games often draw the user into the their story, involving the user in the characters lives, so that when something happens to the characters the user feels emotions connected with it. This type of syndrome can be experienced mid-game if say, your favorite character is killed off, however it usually only appears at the conclusion of the game, wherein the story reaches its conclusion and the feeling of sadness is created by either the events in the conclusion, or simply the fact that gameplay, and the storyline is not over. This syndrome usually lasts at maximum one day, and can be cured by the purchase of a new video game which is equally involving. There is also some evidence to suggest a similar syndrome exists with "books" however this is impossible to test since the art of reading has been lost for many years.
Dude 1: Hey man whats wrong with Jack?
Dude 2: He just finished playing Mafia II and now he's upset at the ending
Dude 1: Oh right...Video Game Ending Syndrome... I had that when I finished Red Dead Redemption...poor guy.