In 'Downsizing,' confounding expectations only goes so far

'Downsizing' stars Matt Damon as a man living in a world where scientists have come up with a way to shrink humans as a way to save the planet from overconsumption.

The premise of “Downsizing,” starring Matt Damon, is promising: In the near future, scientists have come up with a way to shrink humans down to five inches as a way to save the planet from overconsumption. If you’re small, you get to live like kings and queens in a little-people community called Leisure Land because your money will go exponentially further.

Alexander Payne, who directed as well as co-wrote the script with Jim Taylor, has made some marvelous movies, including “Sideways” and “The Descendants.” For its first half hour or so, I thought “Downsizing” was going to be marvelous, too. But once Damon’s Paul, an occupational therapist, decides to take the plunge and get small, the film gradually loses its satiric bearings and morphs into an eco-apocalyptic fantasia in which Paul, aided by a feisty Vietnamese rebel, Ngoc Lan Tran (Hong Chau), exposes the iniquities of their brave new world.

Payne doesn’t make that many movies, presumably by choice. Could it be that, not knowing when he might direct again, he decided to make a mashup of his many different movie ideas? “Downsizing” never quite goes where you think it’s going, and normally, I’d say that’s a plus. But confounding expectations only goes so far. You still have to get to a place worth getting to. Grade: C (Rated R for language including sexual references, some graphic nudity, and drug use.)