Has any musical been so proudly … well, shabby, as Little Shop of Horrors? The classic 1982 show—and the 1986 Frank Oz movie it inspired—is like a parody of a bad sci-fi movie. The flowers in the floral shop where most of the action takes place are supposed to look like plastic, the characters’ accents (Long Island?) from their decrepit neighborhood Skid Row are intended to be cartoonish, and the giant alien plant that feeds on blood is meant to seem a little fake.

Fittingly, Constellation Theatre Company’s production leans into the camp elements of the musical with full force. Under the direction of Nick Martin, this adaptation is unfailingly faithful to the source material—no jokes about millennial plant culture here. It’s a reminder that sometimes, a straight-ahead production that lets its cast find something new in a well-trod script is exactly the move.

As Seymour, the loveable nerd who starts feeding blood to an alien plant, Christian Montgomery’s winning performance is as much physical as it is in the “aw shucks” dialogue. He stutters through his many scenes, with posture that any Toastmasters coach would clock. Montgomery manages to find chemistry with all his stellar costars, especially Teresa Quigley Danskey as Audrey, the battered coworker Seymour crushes on. She has perhaps the toughest job in the group: She manages delicate vulnerability with Lucille Ball comic energy and rafter-reaching notes on her the show’s signature song, “Suddenly Seymour,” all without aping Ellen Greene’s iconic Audrey from the film.

A sense of physical comedy is something all the performers here share, especially Scott Ward Abernethy’s evil Elvis Presley swagger as Audrey’s no-good boyfriend Orin (though Abernethy’s performance does include a short turn in drag, an “it’s funny cause he’s dressed as a lady” bit that’s every bit as dated and tired as it sounds). A street urchin trio-slash-Greek chorus, Chiffon, Ronnette, and Crystal—see? campy—are played by Selena Clyne-Galindo, Alana S. Thomas, and Chani Wereley, respectively, and are similarly chameleonic, channeling powerhouse doo-wop stars one minute, and smart aleck teens the next.

And then there’s the plant, bloodthirsty Audrey II, who, when finally revealed in full size to the audience, elicits gasps. Marty Austin Lamar voices and Rj Pavel operates the multiple Matthew Aldwin McGee-designed puppets that grow larger throughout the show. She takes up about a fifth of Constellation’s teeny set, which actors already have to scoot around. But in a way, that’s just right for a scrappy show like this.

Constellation Theatre Company’s Little Shop of Horrors runs at Source Theatre through Nov. 17. Tickets $25-$55. Runtime approximately two hours with one 15-minute intermission.