There have been several movies that feature a character living in a world that is not what they think it is. Many of them, like Room, Dogtooth, Bad Boy Bubby, and The Truman Show, are surprisingly good. Brigsby Bear continues that trend.

For as long as he can remember, James (Kyle Mooney) has been living in a survival shelter with his parents, Ted and April (Mark Hamill and Jane Adams). Something has happened to the world, and it’s not safe to go out without respiratory protection. About the only form of entertainment James has is a television program called Brigsby Bear, and he’s obsessed with it. But the air is not poisoned, and Ted and April are not James’s parents, and Brigsby Bear is not a real TV show. Ted and April abducted James when he was a baby, and Ted, a former animatronics engineer, has been making the show exclusively for James.

Police finally catch up to Ted and April and James goes to live with his real parents (Mark Walsh and Michaela Watkins) and sister (Ryan Simpkins). He’s confused and culture shocked, and neither Detective Vogel (Greg Kinnear) and Dr. Emily (Claire Danes) are of much help. Then James meets one of his sister’s friends, Spencer (Jorge Lendeborg, Jr.), who is interested in filmmaking and offers to help make a movie to provide closure to his favorite character.

The “twist” that James’s life isn’t what he thought it was isn’t really a spoiler because it’s revealed early on, and because it’s pretty clear that something fishy is going on even before we actually get confirmation. The plot is engaging and important to the film, but the movie is really about James coming to terms with his new reality, and other people coming to understand him.

This movie is much less dark and much less of a downer than most other films of this type. It’s funny and sweet and thoroughly enjoyable. You don’t really care that the basic premise isn’t all that believable. You’re also not too concerned about how quickly James makes friends with teens who are much younger than he is and you think would be much more prone to avoiding or making fun of him. Minor quirks like these just add to its charm and keep it moving along so that it can focus on what’s important, and it’s just so much fun that it’s easy to overlook the flaws and let yourself be taken in by the movie.