Tammy

Melissa McCarthy’s title character in Tammy is a bit like a female version of Homer Simpson — overweight, boorish, clumsy and perpetually unlucky. But what she’s missing in comparison to the iconic father from the cartoon sitcom is charm.

Instead, Tammy is abrasive and obnoxious, and doesn’t earn the sympathy she craves in this self-styled, semi-improvised comedic vehicle for McCarthy, who might be better off stretching her talent in a different direction.

She helped lure a top-notch cast to this low-brow redemption story about a middle-aged woman in need of a fresh start. McCarthy co-wrote the script with her husband, Ben Falcone, who makes his directorial debut.

At the outset, Tammy has every reason to be upset with the world. Her clunker of a car is totaled, she gets fired from her fast-food job, and she comes home to find her husband (Nat Faxon) having a romantic dinner with a neighbor (Toni Collette).

Broke and desperate, she knows that moving in with her mother (Allison Janney) isn’t an option, prompting her to embark on a road trip with her grandmother, Pearl (Susan Sarandon), a feisty alcoholic who has enough money to sustain them for a while.

Plenty of complications ensue, of course, such as when Pearl meets a suitor (Gary Cole) at a bar, but his son (Mark Duplass) doesn’t take the same interest in Tammy. After getting into trouble with the law, they seek out Pearl’s lesbian friend (Kathy Bates), who provides shelter and inspiration for Tammy to turn her life around.

The screenplay contains some big laughs scattered between a series of labored and uninspired gags that don’t play to the strengths of its stars. In particular, a pivotal robbery sequence completely overstays its welcome.

Within the familiar road-trip framework filled with eccentric sidekicks, there are the abrupt transitions between broad comedy and more serious family drama that feel consistently awkward. Sarandon seems to have fun in her freewheeling role — the fact that she’s only 26 years older than McCarthy in real life is obviously part of the joke — but her drunken shtick grows tiresome.

Given her recent track record, perhaps McCarthy is trying to position herself as the contemporary queen of raunchy comedies. Yet in this case, Tammy seems like a lot of huffing and puffing without sufficient payoff.

Rated R, 96 minutes.