According to IMDB, this is the plot.
"Pleasantview is one of the most delightful neighbourhoods to live in, everybody is happy, the grass is always green, children are always well-mannered. But newcomer Andie starts to uncover the 'real' pleasantview, for not only are Pleasantville full of cheating, lying, decieving, secret-ridden people like the Goths, Don Lothario and the struggling Newbies, but they are being ruled by a greater power. Andie is terrified to discover they are stuck in a video game being played by millions universally"
Yet the also have this listed as the plot.
"A young woman, Mary Waldeck who is a budding reporter,moves to Pleasantview too. She soon realizes to her horror that everyone in pleasantview is being subjected to a great new live human experiment, and have had their brains implanted with the idea that they're actually in a universally popular video game, and that their names even are the names of the people from the game itself. All except for Andie who becomes Mary's poor insane accomplice driven out of his mind from what the scientists of the world had been doing to him, but also determined to save himself and the other citizens of Pleasantview."