This is a video denouncing the "videogame addiction", a sort of "public service announcement."
In the plot of the video our protagonist,
that is Kyon plays about 8 consecutive hours playing a new game that he just bought.
Suddenly Kyon has hallucinations, but he is convinced that these hallucinations were a nightmare, because they are vanished.
Instead, the hallucinations continue, and he'll be blocked into the game, and also in the DVD cover,of the game that he was playing.
Until the end when he wakes up in his bed conscious that it was a dream.