First, I have to answer some questions about games themselves. Can games be artistic? Is there art involved in creating games? Of course. But can a video game itself be considered a work of art? The answer is simply no. A game is a GAME...not something that can be experienced that a normal piece of art could be normally. Video games are defined by a set of rules, boundaries, and have some sort of end goal. In art, at least many forms of it, do not boundaries. Art can be interpreted openly and freely, in the eyes of the beholder.
Video games have a level of interactivity that no other medium has. It has a personal interaction with the player. Sometimes that interaction is an emotional experience, bringing the player joy, sadness, or even a sense of dread and fear. But this said interaction is sadly what prevents a video game from being art. Art does not have this level of interaction with a viewer. Art can elicit these emotions, but the artist does not grant the viewer with interaction. To simply gaze upon a painting is just that--gazing and experiencing what is before you.
This subject is really hard to fully explain, but interacting with something does not make it art. In a video game, it is often times a directed experienced, and you are being lead down a particular path, and more often than not to achieve a very specific goal. Art does not have this particular aspect. The artist might have a particular goal in mind for the piece of art, but person experiencing the art would not know what that goal is. Art is in the eyes of the beholder.
