Before I decide to play a game, I see a lot of screenshots, gameplay videos, trailers, concept art -- in other words, the graphics. If the game doesn't look good, that can turn me off of playing it.
But once I get immersed, the graphics go away. The sprites/polygons become people, buildings, streets, what have you. Unless the art suddenly changes style or something doesn't jive with the color scheme or the graphics glitch out or some important item blends in with the background, I don't even notice.