The biggest factor in determining whether or not something is art is intentionality. If the maker had something in mind when they made the piece that was beyond "I'm going to make a football game," then it has a good chance of being art. There are other factors, but none of them seemed as critical as that one. Selling games is a factor, but it clearly can't be that big of a factor, because thousands of awful games get made every year. Shoot, the other day at GameStop, they were throwing out a pile of PC games that weren't selling, one of which was an Italian wedding-planning game. If sales were the only thing that the creators had in mind, then they obviously wouldn't have put that game out there.
The main point is this: if the artist/creator had an intention in making the game that was beyond a desire to make the game itself, then it is art. If the intention is solely to evoke a response from the viewer, that's fine, and is the basis of most shock art. The art can not be created by someone who wouldn't understand intention, however. For example, the elephant who paints pictures is a novelty, but could not be considered in artist, because it has no concept of intention, and furthermore, would not paint outside of captivity. Similarly, pieces of art that are made by computers could not be considered art. I'm not talking about digital art, but rather computers that compose music or design art based on computer programs. While the programs themselves can be extremely complicated, they do not create "art" because there is no intention.
There is a world of difference between what is considered "art," and what is considered a "craft." That is not to say that something that is a "craft" is inferior to a work of art; a photo-realistic rendering of a face, a la Chuck Close, is much more appealing to me than a canvas painted a solid color. Not to say that Chuck Close has no intention, and that it is not art, but something can be aesthetically pleasing and still not be "art." Once again, however, Chuck Close was an example (and my favorite artist) and by no means do I intend to diminish his art in any way. What I'm saying is, the physical work of art itself is simply a means to express a message, yet can never be separated from the message. Similarly, the message attached to the art is what gives the art meaning; if separated, both lose meaning.
So to tie it back: if the creators of video games have intention in creating said video games, and they are able to evoke a response, than they should be considered art, without a doubt.