The game, OReilly’s second ever, is highly conceptual. There are no clear objectives, no rewards, no sense of progression. The only purpose, if it can be characterized as such, is to interact with and inhabit any object on the screen. In other words, anything you see, you can be. A rock. A cedar. A sun. How long you explore the game as any given object is entirely your choice. The purpose of Everything is so simple, so untethered to traditional gaming conventions, that it’s easy to worry about whether you’re playing it right. But the game encourages players to let go of those anxieties. “Don’t get discouraged,” a towering cedar might say. “Everything here is to help you.” OReilly was partly inspired by the late British philosopher Alan Watts, who in the 1950s and ’60s popularized Eastern ideas of universal connectedness. Throughout the game, short audio clips from Watts’s lectures on perception and the structure of the universe appear on the screen and can be played. “He is describing in words what the game is describing through image and sound,” OReilly told me.

Scenes from Everything

Everything is part of a growing movement of independent games that blur the boundary between art and entertainment. “Digital distribution has opened up a lot of opportunities for smaller-scale, more challenging experimental work to find an audience,” Frank Lantz, the director of the Game Center at NYU, said. While commercial publishers used to be conservative, often “burdened with the legacy of escapist adolescent male power fantasies,” according to Lantz, they’re now taking notice, supporting projects that overturn conventional notions of what a game is and add artistic prestige to their lineups. “It’s kinda like showing a Stan Brakhage film next to Guardians of the Galaxy at the mall movieplex.”

Some of the high-prestige indie games that made their way onto Xbox and PlayStation include Journey (a melancholy pilgrimage to a mountaintop in which you sometimes encounter other random players), Gone Home (players explore an empty house in Portland, Oregon, and un-lock its secrets through hidden journal entries), and What Remains of Edith Finch (a narrative adventure published by the video game arm of the film production company Annapurna Pictures).

OReilly is something of a Michel Gondry of the gaming world. At 14, he started working for a small animation studio in Kilkenny, Ireland. (The studio, Cartoon Saloon, went on to make the Oscar-nominated film The Secret of Kells.) After a three-year stint in London, where he worked on a music video for Beck and animation sequences for the 2005 film The Hitchhiker’s Guide to the Galaxy, OReilly moved to Berlin to start making his own animated shorts. “It was a disaster,” he said of his first attempt, which he refused to describe. “So then I was like, fuck — I have to do something else.”

His next animated short, Please Say Something, about a cat and mouse “with a troubled relationship,” won a top prize at the 2009 Berlin International Film Festival. It was a perfect example of his graphically minimalist style. “In animation in general, you’re taught how to decorate things — and my thing is: How do I strip it down?” OReilly said. “It doesn’t have to be perfect, it doesn’t have to be beautiful.” One of his most popular films, The External World, which premiered at the Venice Film Festival in 2010 and Sundance in 2011, is composed of a series of characters — crudely drawn, almost nightmarish — in absurdly bleak circumstances; in one, a crying girl pulls tissues from a box, which yells in pain.

His wry style soon caught the attention of Spike Jonze, who asked OReilly to be the animation director for his film Her. OReilly spent nine months working on three minutes of animation: a scene in which the movie’s lead (Joaquin Phoenix) plays a video game featuring an alien with a shockingly foul mouth, voiced by Jonze. “The alien — that’s the essence of Spike,” OReilly said.

After Her wrapped, OReilly was exhausted. He began questioning whether his career was headed in the right direction. “I know people who make animated shows for TV, and they don’t have lives I envy.” So he decided to try his hand at making a real video game. “The difference between games and animated shorts is that people are actually interested in paying for the former.”

When Double Fine Productions, a San Francisco video game developer, heard of OReilly’s interest, they offered to publish his work. OReilly’s first game, Mountain, was released in 2014 through the iTunes App Store. There’s a mountain: It spins, stuff grows on it (trees, plants) and things fall from the sky (bicycles, vehicles, furniture, baked goods). It rains, it snows. It goes on for about 50 hours. You can rotate the mountain, zoom in and out, and play it songs. The reviews were mixed, encapsulating a long-running debate in the world of interactive entertainment: What makes a game a game? “People were expecting a funny thing,” OReilly said. “But it’s not intended to be funny. It came from a sincere place.”

Mountain garnered enough acclaim, however, that PlayStation signed on to distribute Everything, which was released in the spring. Reviews have been far less polarizing, with most praising the game’s inventiveness (a critic from Polygon, the gaming website, characterized it as a “magical playpen”).

Back at SFMOMA, several more gallery attendants had stopped what they were doing to watch OReilly, now inhabiting a human tooth on the screen, make a cluster of other teeth dance. “OK,” he said. “I’m going to show you the secret to this game.” He set down the controller. After a few seconds, the game began to play itself. The teeth danced on their own.

“It’s basically an installation piece at this point,” OReilly mused before the crowd, as the world he created kept spinning on without him.

(Recommended by Rick Thomas, H.W., m.)