Somebody once had the idea of having a film critic watch a movie with a preview audience and lead a discussion immediately after the show. The title offered to me was a little thing called “Pretty Woman.”

This was a week before the movie opened. When the lights went up, I said something about how it was expertly made and that Julia Roberts was clearly going to be a huge star, and I also mentioned a few things about the film’s shortcomings, its cliches, and its somewhat weird ideas about prostitutes and wealthy men.

The audience did not want to hear that. No sir. Nobody wanted to listen to some wet blanket yammer on after they’d just watched a modern fairy tale.

Because “Pretty Woman” practically launched the contemporary romantic comedy, it makes sense that “Isn’t It Romantic” begins with a dissection of that 1990 movie’s shortcomings and cliches. This new film is a romcom disguised as an anti-romcom.

Our heroine, Natalie (Rebel Wilson), watches “Pretty Woman” on TV and has some thoughts. She knows romcoms are a lie, that there’s no Prince Charming, and that rich men don’t marry working girls. (I wished she complained about watching “Pretty Woman” in the wrong aspect ratio, but don’t get me started on that.)

After a head injury — is this a trend now, after last week’s “What Men Want”? — Natalie wakes up and finds her dreary world transformed into a dazzling, brightly lit romcom, in which her apartment is 10 times its usual size and people break out into song and dance to express their joy. “How did everybody know the choreography?” she wonders.

Oh, and the rich guy (“Hunger Games” dude Liam Hemsworth) who’s been dealing with her architectural firm is suddenly showering her with attention. Natalie notices that every time they’re about to have sex, the film cuts away. Also, when she uses the F-word, there’s always a loud noise on the soundtrack.

Her life has become PG-13.

“Isn’t It Romantic” is all very wink-wink about serving up the romantic comedy tropes: Natalie gets a gay best friend (Brandon Scott Jones) whose mannerisms are over the top, and her perfectly nice assistant (razor-sharp Betty Gilpin, from “Glow”) inexplicably becomes a nasty rival.

She also realizes that the nice guy (Adam Devine) in her office likes her for who she really is. Of course, the audience knows this from the first five minutes of the film, as we always do with romcoms.

“Isn’t It Romantic” is a mixed bag; it scores with “Pitch Perfect” comedian Wilson’s shade-throwing persona, but generates a sour aftertaste in how often it pats itself on the back for being clever.

That’s the tricky thing about genre spoofs — you risk telling the audience they’re idiots for liking a certain kind of movie. It’s almost like embedding a critic in your film, and believe me, nobody wants that.

“Isn’t It Romantic” (2 stars)

Rebel Wilson plays a cynic whose life is transformed into a movie romcom after a head injury. Wilson’s wisecracking persona gets some laughs, but the film tries to have it both ways: making fun of the cliches of the romcom, but also embracing them. With Adam Devine.

Rating: PG-13, for subject matter

Showing: Alderwood, Alderwood Mall, Everett Stadium, Galaxy Monroe, Marysville, Stanwood Cinemas, Meridian, Oak Tree, Pacific Place, Seattle 10, Woodinville, Cascade Mall.t