That Thing You Do! was written and directed by Tom Hanks, his first directing effort. His direction is sure-footed and shows a real love for the time period. Also, he wisely cast the film with then-unknown actors, including Liv Tyler and Charlize Theron in early film roles. These unknown, likable actors, more than anything, are what invest the audience in the story. The kooky, young guys who make up the Wonders are believably blindsided by their sudden success and aren't quite sure what it means or what to do with it. Through it all, they crack jokes, they fight, all without realizing just how fleeting their success will prove to be.
And, finally, there's the title song, the one that launches the Wonders into their sudden success. Written by Fountains of Wayne bassist, Adam Schlesinger, the song does the nifty trick of actually sounding like a 1960s hit without becoming a cloying irritation from its repeated playings throughout the movie. On top of that, the song also connects to two of the characters in the story. It is one of the most masterfully written songs for a film.
Like I said before, That Thing You Do! isn't a cinematic masterpiece, but it is an enjoyable and well-meaning film. A good, solid film from start to finish.