He then extended his theory to all artists. “You see it most clearly with films in the lust to be able to put at the end of the film, ‘This is a true story,’ ” he said. “And in the scramble for the ‘real world,’ whether that is in ‘reality television’ or any other form.”

Yet video games have proved nearly impervious to this anxiety. The medium remains stuck in what might be called its epic-poem phase, relying on static, larger-than-life characters whose exploits are explicitly fantastical: wizards, aliens, zombies, future soldiers and space marines.

And video games have hardly dipped even a toe into the waters of nonfiction, with the exception of sports, re-enactments of historical battles and provocations like the 2004 release J F K: Reloaded (which asks the player to adopt the role of Lee Harvey Oswald in the Texas School Book Depository). A few years back the very notion of a video-game documentary about the war in Iraq was so explosive that the project, Six Days in Fallujah, was shelved by its publisher, Konami.

That’s what makes Papo & Yo, a game released last month on Sony’s PlayStation Network, so remarkable. Papo & Yo is a magical-realist fable about the relationship between its creative director and writer, Vander Caballero, and his alcoholic father. No, the game isn’t an autobiography or a documentary, or even nonfiction. But its power is amplified by its relationship to actual events from its creator’s childhood — and by the player’s knowledge of that relationship. It feels like a landmark.

“To my mother, brothers and sister, with whom I survived the monster in my father,” reads Mr. Caballero’s dedication at the start of the game. A bit on the nose, you might say. But when an artist is working in a medium that has almost no history of memoir — or even of “Pan’s Labyrinth”-style allegory — he can be forgiven for wanting to make sure the project is understood.

Nearly all of Papo & Yo is set in a Brazilian favela, whose colorful structures of corrugated metal, Spanish tile, wood and cinder are familiar to players mostly as a killing field in games like Modern Warfare 2 and Max Payne 3. Here, however, the only violence in the shantytown is inflicted upon Quico, the boy who represents Mr. Caballero, by the creature who represents his father: a pink, rhino-horned beast known only as Monster.

Monster is no villain, though, and no malevolent force to be defeated. He is brutish and powerful, but also pitiable. Monster cannot control his anger after consuming frogs — an irresistible delicacy — and Quico, knowing that this is not entirely Monster’s fault, is on a quest to try to cure him of his sickness. Monster is also kind and, well, fatherly. At one point he reaches down to rescue Quico from a pit and then shakes his head disapprovingly.

If all of this sounds quite unreal, that’s because it is. But Papo & Yo continually reminds the player of the story’s underpinnings. There are flashes to a darkly mysterious night in an alleyway. A frightened Quico clutches a toy in the back seat of a car as his father stands in front of the headlights, which cast Monster’s silhouette on the wall behind him. This is inspired by a true story, and Mr. Cabellero and his colleagues at Minority Media, the Montreal studio that developed the game, won’t let you forget it.

Players looking for brain-teasing puzzles or invigorating action will find little to please them. The core activity is interacting with gears that are drawn on walls in the favela, a simple task that leads to a surreal reordering of the structures in the world. The gameplay functions more like plot — I wonder what this will do? What happens next? — than as challenge. (The only real challenge occurs when moving Quico from platform to platform in some of the later levels, and it feels unintentionally exasperating.)

An excessive devotion to difficulty “limits what games can do,” Mr. Caballero told the games Web site Bit Creature recently. “I want Papo & Yo to be challenging emotionally,” he said. “I don’t want it to be challenging dexterity-wise or logic-wise, because emotion and rationality do not gel together.”

For decades video games have made grandiose claims about their realism — in graphics, in simulations of sports and war — that can seem, in hindsight, laughable. Go to YouTubeand watch George Plimpton hawk Intellivision consoles in the early 1980s by lauding the realism of a baseball game for a representative example.

Now Papo & Yo, a lyrical tale of a boy and a monster, has set a new and altogether different standard in gaming for representing the world as it is.