On Going Topic question part 1: Are video Games Defined by Graphics or Gameplay?

Well I was playing 'Call of Duty: Black Ops' I was asked the question; are video games defined by graphics or gameplay?

You know, well I was playing this game, I'm not sure if it was because the brightness was turned down or not, but I found it at times rather difficult to see, and in all honesty, for a game that isn't from the early 2000's, I don't think it's aged graphically to well. However, I can get by that, as the game play is pretty solid, and I was able to get back into the flow of things pretty quickly (which could be a good or bad thing). Overall, though, well the game play is repetitive, and as much as COD players are criticized for only caring about the graphics, I really don't think COD became as popular as it is today solely because of it's graphics, but rather due to it's easy to learn game play.