Amusingly, the phrase "Citizen Kane of Video Games" has inspired a Tumblr blog. It draws quotes from articles hither and thither around the web about whether Game X might be the one, or whether the debate is irrelevant. Can games ever reach this lofty goal? Was Super Mario Brothers actually it? And so on. The "Citizen Kane of Video Games" is as old as games have been discussed, the very definition of a circular meme.
The meme comes from Welles' film being storied as a breakthrough which managed to define an art form on its own terms. Critics celebrate it as the one that really got what film could do. But in the games industry it's also associated with game makers who hold to narrativist thinking and believe that games are the future of storytelling. This is why the label often gets attached to games with highly cinematic overtones (The Last of Us, The Walking Dead, etc) or zines like Proteus. The ones that are trying to be anything but games.
Though various pretenders may have emerged, their claims rarely last because they're not really breaking through anything. Such games are more the equivalent of staged movies of the '10s, '20s and '30s, the ones that pretended to be theatre. They have an increasingly formalized way of doing what they do and have had for decades. They cover the same ground over and over, relying on the same ways of delivering their content. Arguably they have, much like opera, fallen into a series of fixed tropes that leave little room for exploration. Maybe the writing is great in places, but they feel as artificial as ever.
While The Last of Us is superb, it's not transformative. Its mechanics have clear links to other games, as do its narrative tropes. Evolution not revolution perhaps. Innovation not invention. Masterwork not founderwork. Portentous and self-serious it may be, yet the mechanical component and the fun of overcoming challenge remain the primary driver. In many ways it's every bit the sneak-and-stab game of a Metal Gear Solid or a Splinter Cell. There is an archness, a tension born of wanting to be like another art and essentially graft a game in.
Focusing on the meld between urgency, fiction and machine is what games do better than any other art form. There are many examples of games that do this and are not tacitly embarrassed about being fun. The tragedy is how many commentators of the form seem to want it to be anything but, and so perpetually circle the drain of Citizen Kane.