Fitting snugly between the devastating Room and the uplifting The Truman Show, you’ll find Brigsby Bear, the only laugh-out-loud movie about infant kidnapping that involves talking, magical members of the Ursidae family.

Starring and co-written by Saturday Night Live’s Kyle Mooney, directed by S.N.L. shorts and Epic Rap Battles of History alum Dave McCary and produced by The Lonely Island, Brigsby Bear starts with an outstanding “what if?” It follows through with fantastic characters and funny set-pieces, building to a warm and admittedly fabulist conclusion. It’s going to sound a little corny, I’m warning you—but when you come out the other end, this story is a bit of feel-goodery that is earned, unlike so many indie films that get stuck in a morass of their own well-meaning quirk. Every future Sundance applicant needs to watch this movie and take notes.

Granted, I’m a mark for anything that wraps its arms around extreme fan cultures, and I have great empathy for someone who draws strength from a “deep mythos” entertainment property. But Mooney’s wide-eyed, big-hearted, eternally-grinning James isn’t just a hardcore fan. For him, the cheapo children’s show Brigsby Bear (not quite H.R. Pufnstuf, not quite Teletubbies; more like The Great Space Coaster) is more like a religion.

From his room in the strange, geodesic dome in which he lives with his parents (Mark Hamill and Jane Adams), James obsesses over each new VHS tape of Brigsby when it arrives each week, and makes art projects exploring the themes of the show. Just when you are ready to buy that James is living in some post-apocalyptic hellscape, police come and “rescue” him.

It turns out that he was stolen from his real family as a child—but James’s biological parents (Matt Walsh and Michaela Watkins) never gave up on searching for him. Now the long road of reintegrating him into society after 25 years in a children’s television Skinner box has begun.

But all James cares about is the next Brigsby adventure, and he is quick to ramble about the show’s rich lore of wizards and orbs and various weapons of light. (I am dying to read a glossary of terms for this make-believe show.) There are, unfortunately, no new episodes for James; as it turns out, Mark Hamill’s character, an electronic-plush toy tycoon, created the show himself on a nearby soundstage. (Ah, that’s why one of Brigsby’s catchphrases was “Curiosity is an Unnatural Emotion.”)

Eventually, James forms a bond with his high school-aged younger sister and her friends (after an amusing fish-out-of-water house party), and all agree that what James needs to do is finish Brigsby’s story. Without going too far into Be Kind Rewind territory, the creation of this home movie is a hoot. James learning how to socialize is surprisingly touching, too, as is the local deputy, played by Greg Kinnear, using this opportunity to rekindle his love of acting.

Brigsby Bear’s strongest asset (well, after the gobs of in-universe verbiage that come spilling from James’ mouth) is Kyle Mooney’s extraordinary performance. By and large, James understands what’s happened to him, and that Brigsby isn’t real—but that doesn’t make the show less important in his eyes. When he meets the woman who played the “Smile Sisters” on the show (Kate Lyn Sheil as a diner waitress who showed up at the studio each month for a little extra money), she expresses remorse over her small, unwitting part in perpetuating this now-famous “kidnap kid”’s nightmare.

But James doesn’t see things that way at all. She was part of the show he loved—the only entertainment he ever knew. And while he realizes she was just reading lines, he still addresses her as the focus of his lifelong obsession. It’s a sad moment, but also funny as hell thanks to Mooney’s mastery of deadpan delivery.

Brigsby Bear is in some way the quintessence of a Sundance film, and for some that may have negative connotations. Off-kilter as it is, though, the film has the characterizations to back it up. The ending drags on a bit too long, but that’s understandable. To hang around James and soak up some of his positivity (even if it is a little unclear if he knows what’s going on half the time) is a joy—and who would want to be cut off from that show so abruptly?