1 definition by Rick Nomere
A sense of extreme euphoria brought about by experiencing great amounts of both nostalgia and sheer awesome in a short amount of time. Usually less than five seconds. The effect is likened to being a reverse-migraine.
I hadn't played Super Mario Bros in years, so when I beat Bowser yesterday there was almost an immediate phantasium that followed.
by Rick Nomere October 1, 2007