A game developer is able to offer more to their player than any artist before. Previous artists have been shackled by their inability to affect the audience past the point of delivering an experience onto them. You can't get onstage in a play and slap an actor. In a museum, you can't change a painting if you don't like the color. Traditional art doesn't interact with the viewer.
Games are bottled and flavored experiences.
Every game of Dead or Alive 2 or System Shock 2 or Quake3Arena changes you as you change it. You aren't passive, you are both actor and audience. This is why gamers feel so passionate about games they love - because it's personal. It's also why gamers feel so much hatred for games they hate - because it's a personal affront. At least that's what I think.