Kristen Wiig as Annie
Maya Rudolph as Lillian
Rose Byrne as Helen
Ellie Kemper as Becca
Melissa McCarthy as Megan
Wendi McLendon-Covey as Rita
Chris O’Dowd as Officer Rhodes
Jon Hamm as Ted
Matt Lucas as Gil
Rebel Wilson as Brynn

The whole world is against Annie (Kristen Wiig). Her one shot at the American Dream, a cake shop, was eaten by the Great Recession; she’s forced to live with a pair of obnoxious roommates so that she won’t have to move back home with her mother; and her quote-unquote “boyfriend” is only interested in her for sex and isn’t even decent enough to hide the fact. Then her best friend (Maya Rudolph) announces she’s engaged and things start to really go downhill.

First off, you’re going to have really like co-writer/star Kristen Wiig’s particular brand of woman-on-the-verge-of-a-nervous-breakdown humor, because that pretty much sums up the entire film. Wiig has been honing that joke for quite a while on “Saturday Night Live”–an uncharitable person might say it’s the only one she knows, but that’s not entirely fair–so it’s to her and director Paul (“Unaccompanied Minors”) Feig’s credit that “Bridesmaids” doesn’t feel like an SNL sketch stretched past the breaking point.

A lot of that comes down to the script by Wiig and writing partner Annie Mumolo. They prove they can do low-brow scatological humor just as well as producer Judd Apatow. Even better, they prove they understand how to make it work by making it part of being human rather than just an excuse to be over-the-top, even when it is incredibly over-the-top.

Annie’s low self-esteem and any decisions that can be affected by her self-esteem are hanging by a thread to begin with. When she meets Maya’s new best friend Helen (Rose Byrne), who is perfect and put-together as can be, said self-esteem starts to head for the nearest cliff. Unfortunately, because she has been picked to be maid of honor, she invariably drags everyone else down with her. At its best, we get extended, grotesque excursions to the heights of humiliation, like a Brazilian steakhouse-fed dress fitting that goes horribly, horribly wrong.

Unfortunately as much as it gets that sort of thing right, it wallows quite a bit in Annie’s plight, often killing the comedic momentum it has worked so hard to create.

The problem is, for all the strength in her script, Wiig is also the worst thing about “Bridesmaids.” Annie is so one-note and sad-sack it becomes impossible after a while to feel anything but frustration for her. Wiig herself seems to be aware of this as eventually even Annie’s friends feel they have no choice but to hold her on a couch and slap her till she gets her head out of her ass.

That fault is amplified by how much funnier and more interesting everyone else in the film is compared to her. Feig and Wiig have put together a perfectly-gelled cast with truly interesting supporting characters. Even people who show up for just a minute or two, like John Hamm’s unbelievable douchebag, instantly register and often get some of the best laughs of the film.

But those appearances are often fleeting as the movie is solely about Annie’s fight to right her own ship, which turns into a long hard slog and creeps into the cliché as it goes along. With every good decision she makes either going bad or being undermined by Helen, who can’t help but compete with her for Lillian’s affections, Annie creeps ever closer to the edge. If you think there’s a colossal flip out in there where she pushes everyone in her life away, I wouldn’t bet against you. If you want to add a montage to that bet, I definitely wouldn’t take it.

Wiig may actually be as good a performer as she is a writer, but it’s hard to tell because her best qualities are smothered under the one-note patheticism she has chosen as her main gag. “Bridesmaids” is funny and occasionally even warm, it’s just impossible not to feel it would be even better if anyone other than Wiig were in it.