A game isn't art just because It's good. It's art when the creator intended it to be art (this is not a waterproof rule, but in most cases this is true). If the intention is purely to entertain, then it's entertainment.
I see your point, but I have to disagree. Again, I'm not saying that games are high art, the way a painting is. But they are a kind of art. Art with a purpose is still art, though it is a sub-category of art called "craft." For instance, pottery, acting, and furniture design are all crafts... they all require applied artistic skill, but they each have a purpose other than to exist merely as art.
Games are born of the creative process. And while a game may or may not have a message to send, it is still comprised of artistic elements. Those elements however serve a purpose (as we both agree, that purpose is to entertain), and so games fall under applied arts, or craft. Even if your game is made of colored boxes, you still have to call upon your creative process in order to realize it.
Of course there are varying degrees. A simple match-3 game obviously doesn't have the same artistic value as, say, Limbo. Much as a child's stick figure drawing doesn't have the same artistic value as the Last Supper.
Some day, when games are picked up by artists, not geeks, games are going to take a whole new direction. This will probably happen around the time when art schools start to accept game devs, educate them, and push them to do artistic research.
Art schools are already doing this. Perhaps not fine art schools, but applied art or design schools are. For instance, the Art Institute (where I went to school) has a game design program. (By the way I was there for animation, not game design... go figure ) And while it might be a chain school, it is still accredited and all students are required to take not only core academic classes, but core art classes as well, so even if your major is game programming you still have to learn color theory and art history and life drawing, etc.
They are really good games, but chess is a damn good game as well, but it's not designed to express anything or make you think.
I understand what you're trying to say here, but I'd like to point out that chess is designed to make you think like crazy .
At any rate, chess as a concept is not art. You are correct. Is is purely a game. But, a specific chess set with hand-carved pieces is a different story. The skill and creative talent that it takes to make such a set would elevate that particular set more towards art than if you were, say, playing the game in your head. Video games are like that, only they are intrinsically linked to their pieces, so to speak. Mario Kart isn't a game concept in the way that chess is a game concept... you can't walk into a store and purchase a different "brand" of Mario Kart that was made by a company other than Nintendo. Yes, there are lots of kart racing games out there and they are all somewhat similar, but you can't just up and decide "I am going to make my own Mario Kart" specifically. Well, you could, but that would be like saying "I am going to paint my own Mona Lisa." There is only one, it's not really yours to paint.
Tetris on the other hand has become more like chess in that regard. It's ubiquitous nature has allowed it to transcend the original game and become more of a concept that just about anyone can put their own spin on, even if you can't legally call your creation Tetris.
When we talk about art and games the focus is almost always on the aestethics, audio story and intent of the games. While those are all fine and valid points of discussion I think the scope of discussion has become stunted. A large part of what makes games games is the mechanics and I think that the discussion needs to encompass that as well, because that is what makes games unique.
Take previously mentioned Tetris for example. Why can't that be considered art? Sure it doesn't have an intended meaning, but it doesn't have to. You can easily derive meaning from the mechanics alone if you wanted.
To continue the Tetris discussion...
As I said before Tetris has pretty much been reduced to a set of rules rather than a specific work. Pick any one Tetris game or clone and you can say whether or not that specific work is art, and to what degree. Much in the same way that you can point at any one particular chess set and judge it on it's artistic merits. But the mechanics themselves are purely game. They are a set of rules. It's no more art than the concept of chess, or poker, or hopscotch. But that is Tetris specifically.
As for the rest, I'm just thinking out loud here... I have yet to fully form this idea so bear with me:
As far as game mechanics go, they are the medium in which the work is displayed. They are the canvas on which you paint, as well as the raw paint and the brush. They are also the genre in which your work fits. They are the game... what makes your game a game rather than a painting or a movie or whatever. It's a little trickier to see as it's a really complex canvas.
They are also the major factor in what makes your game entertainment (applied art) rather than high art.
The design of game mechanics and their skillful implementation are integral to the experience, in so far as they are necessary to experience the game. It takes equal measures of creativity, critical thinking, and skill to construct a good mechanic. Just as you may appreciate the skilled brushwork of an artist (especially in something like pointillism where brushwork is the key component to the meaning of the image) you can likewise appreciate the clever craftsmanship of a game designer's mechanics.
Good mechanics make the experience more enjoyable, or easier to digest, but they are still just the means by which the work is presented. I have yet to play any game in which the mechanics were themselves something more than a set of rules and controls by which you interact with the rest of the work.