In many ways, World of Warcraft is a combination of all these media, and yet it is something of it's own too. WoW has vast landscapes to explore, interesting characters with their own meaningful stories, and powerful music to thrill you or spook you or make you feel awe. Not only does WoW combine these elements together in a deeply satisfying way, it stands out as a carefully balanced masterwork of the "game" as a creative human expression. In other words, WoW is basically a web of overlapping problems to overcome alone or as a team, for which all the visual, musical and story elements are metaphors that open the doors into this central element of the game's experience. Not only is it fundamentally interactive, exploratory, and progressive, but your choices, from the way your character looks to the way you chose to play him or her, all represent your own investment in filling out the open space the game has made for you and the community of players. You and your friends are the final keystone in the edifice of the WoW work of art -- your progressive interaction with the game and your cooperation with others is designed from the beginning to be the main stimulating force on your mind and spirit, just as looking or listening is with other forms of art.
Of course art is a subjective thing, like beauty itself. One person may be profoundly inspired and uplifted by her WoW experience, while another may be left shaking his head and wondering why he wasted his time. In their own way, both are right; art is never art without a certain kind of participation by the one looking at it, listening to it, or engaging with it in some way. The perceiver of the art always has to be open to the special impact that art can have on your mind or spirit, and be willing to make that leap of faith into the work of art and see what its creators intended. For some to be unappreciative of one art form or another is commonplace and natural -- people have their unique likes and dislikes after all -- but the fact that a certain work of art touches some people, perhaps many, in a profound way is what sets it aside from mere entertainment.