Length Has Its Shortcomings

“The Minute Waltz,” Mini-Me, a Tootsie roll — some things are made to be short.

To that list, you may add “Saturday Night Live” skits. Eventually, all “SNL” characters will get their own movies and, “Wayne’s World” notwithstanding, that’s not a good idea, since they’re conceived to work best in short sketches. Usually based on a tic or two, the characters grow old fast because they’re entirely based on not having inner lives, on not having any facets that would take longer to explore than three minutes.

Mary Katherine Gallagher may be an exception to that rule, but you can’t prove it by “Superstar.” As played by Molly Shannon, Mary Katherine is the klutzy Catholic schoolgirl who’s addicted to television (” `The Boy in the Plastic Bubble’ is my 19th-favorite TV movie of all time”) and determined to become famous, despite a notable lack of talent.

This “SNL” character has more movie potential than, say, those irritating disco brothers because we can imagine there’s more to her. What’s her family like? Is she aware that other people laugh at her? Is she doing anything to make her dreams come true? These questions occur to us because Shannon is so deep inside Mary Katherine. In some moments, like when she’s singing “Out Here on My Own” in a sweet little voice that grows stronger and more confident as she goes, we sense Mary Katherine has what it takes to get past the pain of being a teenager who is different.

Trouble is, the movie doesn’t see that Mary Katherine is much deeper than the material she’s been given. The “Superstar” script is often dumb, sometimes derivative and frequently mean (Ho-ho. Will “retard” jokes ever get old? Yeah. Forty years ago.).

And it never deals with the fact that these high-schoolers are played by 35-year-olds, a conceit we overlook in three-minute sketches but that is 30 times weirder in a feature-length film.

“Superstar” * Locations: North Division, River Park Square, Spokane Valley Mall and Coeur d’Alene Cinemas. * Credits: Directed by Bruce McCulloch, starring Molly Shannon. * Running time: 1:20 * Rating: PG-13