One thing preventing games becoming a legitimate art form is that people use it purely for the sake of escapism. Very few games ever have any substance whatsoever. Now, I do consider games an art form, and probably the most fascinating one currently available for consumption because it differs so greatly from every other one. I don't want to get into the "games as art" debate, because that's more or less irrelevant, but I bring it up because I don't know if I've ever seen a game face social or ethical problems in the way that books, films, or paintings so often do. Some games hint at them in a general way (Fire Emblem, for instance), but even the best of those games tend to be severely simplified, polarized to good and evil, made abstract and unrealistic to obscure the more serious issues they point to.
People are so passive nowadays, people are hardly ever willing to watch an engaging film, something that raises questions. They'd much rather watch something formulaic. Passive viewing in film is a tragedy, but it's even more tragic when we look at gaming. We have here perhaps the most involving and active form of entertainment/art available, and the most popular games are passive games, games that you can play without thinking. I don't care that Grand Theft Auto is hyper-violent, but it's possibly the most soulless game I've ever played. I won't get into the poor game design, miserable controls, careless visuals and story, but consider the fact that your eyes gloss over when you play the game. You blow up a streetside without considering the consequences, without even feeling the power of that explosion. It's a purely passive game, something meant for immediate satisfaction and nothing else. I despise that. Even if games like Metroid or Mario don't delve into psychological complexities or the ethical challenges facing our social landscape, at least they require coordination and stimulate the mind, intellectually and creatively.
But I would thrill to play a game that didn't shy away from true problems or issues. I don't think every game should be serious, I think you need escapism sometimes, brilliantly simple stuff like Jungle Beat, but we could certainly use a game that expanded our awareness of the world, to show what games could do. I could see a war game that delved into suffering, where you saw more of your comrades dying, maybe your own arm being blown off, seeing children murdered, and less of you gunning down the Nazis and performing heroics. You aren't the hero. You're one of the dozens of soldiers that make up one functional whole. And if you do accomplish anything, you've got to see the full spectrum of your actions. Who you've killed and who you've saved, if you're lucky enough to even manage that.
People would never go for that, not the ridiculous breed of gamers we have to put up with nowadays (not all of them, but the vast majority of them), but it'd be an interesting realm to explore. I wouldn't want it to be exploitive, of course, which would be hard to pull off. But imagine a game where there is no final villain, no saving the world, no heroics, just inevitable failure and obscurity.
I'm kind of rambling, it's very very very late. But I think the fantasy world of gaming has gotten a bit out of hand, and I'd really like to see something that challenged me with more than just a tough boss fight.