For a time, the unapologetic, inorganic cheesiness of Mamma Mia! is charming. Unfortunately, that time is far shorter than 108 minutes — after 40, it feels a bit like scarfing an entire bag of Doritos. No one expects austerity from a movie based on a Broadway show based on ABBA songs, but Mamma Mia! doesn’t even work as farce: when blushing bride Sophie (Amanda Seyfried) invites three of mom’s old flames to her wedding, intending to suss out her father’s identity, everyone just wanders around through undeveloped subplots. Meryl Streep plays the mom, and while she and Seyfried share an enthusiastic, approachable singing style, they’re surrounded by wan men and mugging women (Julie Walters is a chief offender). This traffic jam approach suits the film’s group-heavy choreography, which, to its credit and your potential horror, does resemble actual wedding dancing. When in doubt, director Phyllida Lloyd cuts to an overhead shot, as if insisting that the adaptation is cinematic. She protests too much.