Corpse-stealing aliens are confused by 21st-century suburban Illinois. Zach Clark's promising but too-gentle mix of sci-fi fantasy and social critique is a case in point.

Since Jack Finney’s “The Body Snatchers” was first published 70 years ago, film adaptations — both official and unofficial — have taken place in a small U.S. town, Me Decade San Francisco, a military base, a high school, and so on. They’ve all had one core theme in common: Humanity has been infiltrated and co-opted by a shape-shifting, invading force from outer space. Loosely playing with that theme, Zach Clark’s “The Becomers” adds a new twist, in that this time around, the body-snatching entities aren’t necessarily seeking conquest. They just want to coexist peacefully. But it turns out they may have picked the wrong planet and/or species, as they discover that humanity today may be too screwed up to be worth the effort.

That’s a good starting point for the kind of sly, expressionless absurdism Clark aims for here. But despite the fantastic hook, this episodic tale doesn’t quite reach the oddly endearing black-comedy oddity the writer-director achieved with his earlier films “Little Sister” and “White Reindeer.” A kind of shaggy-dog tale whose appeal wanes as you gradually realize it’s probably not going anywhere, “The Becomers” is equal parts sci-fi, parody and sociopolitical satire. It’s eccentric enough to grab one’s attention, but ultimately too underdeveloped to greatly reward it.

Russell Mael of the long-running cult band Sparks begins with voice-over narration as our nameless, genderless protagonist, providing a backstory—throughout the film’s present tense—of life on a dying home planet. Ultimately, they and their loved one are selected for evacuation, traveling the cosmos in separate travel pods.