I don't think it's necessarily limited to video games. Japan simply has so many strong otaku (original meaning) subcultures to nerd on, anime/manga/game being

I don't think it's necessarily limited to video games. Japan simply has so many strong otaku (original meaning) subcultures to nerd on, anime/manga/game being the obvious ones (to be more accurate, manga in Japan isn't really a "sub"-culture, but the otaku portion of it is big enough on its own). The only things I can think of that are comparable in the Western world are Star Wars or Sci-Fi in general, and Superhero comics. But I'm not super familiar with Western cultures.