Adding something to a game is exactly what graphical realism does.

In point of fact, it is why some games that people remember as great are found to be quite poor or even unplayable upon revisiting ten or twenty years later: Originally, the cutting-edge graphics--and perhaps other aspects like audio, etc.--provided an awe-inspiring experience that invited immersion. This immersion facilitated an ability to abide what was in reality questionable or poor gameplay. The overall experience was impressive enough to endure.

But as a game's technology loses its freshness over the years and its ability to immerse decreases, it is left to stand only on its gameplay. When the "crutches" fall away, the games with solid gameplay remain perfectly playable indefinitely, while the poor gameplay of the rest becomes harder and harder to ignore. It is gameplay--and not nostalgia or the simple passage of time itself--that determines whether or not a game "holds up".

The relationship of graphics to gameplay is analogous to--let's say, steak and potatoes. One does not require potatoes in order to enjoy steak, but if the potatoes are present, their quality has an effect on the entire experience. I don't blame most people for not thinking about this, but take a game as simple as Pac-Man: The graphics play a very large part in the appeal of the experience, as does the sound. The electric blue of the borders, the bright yellow of Pac-Man, the rich colors of the ghosts and the fruit--even the relatively high resolution. And then the catchy music and sound effects. The exact same gameplay can be rendered in black and white, and with no sound whatever--and suddenly the experience is no longer as enjoyable. It's a Pac-Man that's a whole let less 'Pac-Man'.

A video game is the sum of its parts. Being a game, the gameplay is the foundation and the most important. Bad gameplay equals a bad game no matter how well-executed every other aspect is. But in the realm of games, the video game has always been unique as a marriage of gameplay and technological innovation. It has always been just as much about the overall experience as the fundamental gameplay, whether Text Adventure or First-Person Shooter.

I always chuckle when I hear someone (more often than not in defense of consoles) say, "Well, I care about gameplay, not graphics!"**, as if by law one may be wedded to only one at a time. I am reasonably confident that most of those who say this do not, for example, play Text Adventures, so I feel justifiably skeptical at anyone who dismisses graphics as unimportant.

** If this is indeed true, it should be of interest to the console gamer that, since the demise of the AAA PC game industry in 2008, there has been basically zero technological innovation in any area except graphics. Innovation in aspects which have more of an effect on core gameplay such as AI, physics, and audio simulation has stalled or even regressed.