Whoa, whoa -- video games are an art form now? Well, here's the thing: The first rule of art is "art is subjective," and the second rule of art is "ART IS SUBJECTIVE" (the third rule: "If this is your first day at art club, you have to art"), and thus the tiresome argument that video games aren't art is rather moot indeed. Oh, and video games are an output of drawings, writing, and music put together by skilled humans in a manner designed to entertain/enliven, so there's that, too.
So with that out of the way, being on the verge of a new console generation feels like a good time to file something of a progress report on the art form in question (if only to desperately justify those 147 hours I poured into Saints Row: The Third). So what the hell can games do that books and interpretive dance can't?
5 They Can Make You Think Like Someone Else
In a bad video game, you'll tend to refer to your onscreen character as "him" (or, rarely, "her") -- "Look at him fight that giant crab," etc. But a more engrossing game inevitably has you referring to your exploits in the first person -- "I'm sorry, I can't join you for 11 hours of tantric sex right now, I have to kill this giant crab" -- and this is because games can put you in the boots of someone else, to the point where you might find yourself kinda sorta thinking like someone else. Psychologists have long detailed this phenomenon where you'll behave according to what your perceived role in life is, and it's games' ability to harness this in a fun/harmless way that's perhaps unique.
As an example, the Mass Effect trilogy of games (does 2.9 games count as a trilogy?) has a romantic side quest for the main character, and playing as the other gender and then finding yourself genuinely evaluating potential romantic matches from their perspective ("YOU SHALL BRING ME THE BIGGEST HUNK ON THE SHIP") is an experience you can't really get unless the medium is actively telling you to take on another role. A game that more completely focused on all this could be sociologically fascinating indeed (or at least spread appreciation of hunks).
4 They Can Do What Existing Art Forms Can Do, Only More So
What makes a good painting? Arguably you'd distinguish a work of intrigue from a mere illustration by the presence of mystery, or if someone painted boobs on it. Thoughtfulness and ambiguity in an image are the starting point, and the audience's imagination completes the process that we call art. Thus, paintings are cool. But video games can take all this and extend it to the third dimension.
There's an unusually thoughtful and ambiguous game from Japan called Dark Souls that places you in a strange and beautiful undead land with little real direction as to your quest. You'll meet a number of characters, but the narrative and exposition are deliberately kept minimal to foster endless discussion (the game's director loved the process of making up his own stories when reading English fantasy novels as a child and attempted to translate that experience to the video game medium). The game succeeds as a piece of art because the obvious amount of thought and detail that have gone into it subconsciously tell the audience that it's worth their time to try and fill in its many blanks.
You're not told everything, just like you're not told what the hell The Scream is screaming about, only here you've got an added plane of depth, and this is what's known as "taking it up a notch." About halfway through Dark Souls, you encounter a five-story-high painting in a massive, eerie hall. As you approach, some strange force seizes you, pulling you into the painting, leaving you to wander interestedly around the mysterious world within. This is what's known as "literally the most convenient metaphor ever."