Jocelyn DeBoer and Dawn Luebbe are LA comedy actors and veterans of the Upright Citizens Brigade Theatre improv group who are now jointly making their feature debut as writer-director-stars of this elaborately deadpan suburbia satire inhabited by squeaky-clean people with hints of Stepford and Todd Solondz. The title might lead you to think that it is all about envy – the gnawing torment that your neighbours’ lawn is lusher, their SUV bigger etc – but it’s not, or not exactly.

DeBoer and Luebbe play Jill and Lisa, two best frenemies and competitive stay-at-home soccer moms whose husbands do the breadwinning; they live in a manicured little community where people drive around in golf carts. Jill has a strange need to please people, so when Lisa says that Jill’s new baby is adorable, Jill impulsively offers it to her and Lisa accepts.

This weird glassy-eyed trade, accepted as perfectly normal by everyone involved but gradually regretted by Jill like a sleepwalker beginning to wake up, colours the rest of the movie with an air of surreal ghastliness. Strange hallucinatory things happen, semi-symbolic metamorphoses occur, and Jill begins to lose her sheen of perfectness.

Of course, there’s a fish-in-a-barrel quality to this movie’s targets and, as with so much satire, I suspected that “weird” is easier than “funny”. But this grew on me. There is something startling about the TV shows that the children are watching, including a daytime adventure called Kids With Knives, and I liked Jill’s horrified reaction to her stroppy and incontinent child Julian (Julian Hillard) who bizarrely shrieks: “Mom’s a school! ‘I’m mom, full of rooms and clocks!’”

It creates its own unwholesome self-enclosed Percocet aesthetic, and perhaps this is a film for America’s contemporary opioid culture.

• Greener Grass is released in the UK on 22 November.