It's an interesting topic, and one that bears discussing.
I'm of a similar opinion of deadeye on art games. I'm generally disinterested in "art" per se, as the way I see it "art" has mostly always been more about social commentary than the craftmanship of illustration, composing etc.
When talking about art games you'll invariable run into "games as art" territory. Though, it's a separate issue. Art games are art where the artist uses games as a medium, wheras games as art is more about getting games accepted as an artform. Like movies and comics (to an extent) have been.
Following that train of thought. We had a lecturer from Berkley have a seminar about close reading games like they do in literature. It was an interesting lecture and I can see the validity of it from an academic stand-point. But when I, as someone within the industry, look at it matter of factly, what you're doing is literally shoehorning a work into meaning something it probably wasn't supposed to mean at all. Thus, for me, the idea has little use outside of academia.
I have played a few art games, and most of them seem to share a few points. They are often not particularly engaging, which makes me want to 'not' call them games. What gameplay elements there are are often subdued and in the most severe cases "hold this button and the game plays itself" (coughPassage
I'm going to adress some of what you said Granhunter. I don't really get your "90% art, 10% game" thing. What exactly constitutes as art and what constitutes as game? If a game was made with the intention of being an art game, then it's 100% art that just happens to be a game.
"They either grab your imagination, mess with your emotions, or are alot of pretty colors."
I can name pretty much any game and it will correlate to at least two of those. Does that mean that all games are art or that no game can be qualified as an "art game"? Yes and no, simultaneously. There is no good answer I think. It's highly, maybe even completely, subjective.