The endgame of a relationship – or maybe the crisis from which the relationship will emerge reinvigorated – is the subject of this likable, low-key two-hander from Polish film-maker Maria Zbaska. A couple is in crisis; one half is musician Zofia Chabiera who is making her confident acting debut as Wanda, bored and aimless, feeling those first intimations of mortality as people in their late 30s tend to; her unused and thwarted passion is beginning to curdle within her.

Wanda is in a stagnant relationship with Jan, played by Marcin Sztabinski, a heavy-set guy who maybe wasn’t quite as heavy-set when they first got together; he runs a bike repair shop, a situation to which he has dwindled having once dreamed of biking around the world. Wanda is irritated beyond endurance at the way Jan does nothing but doom scroll. (Rather shrewdly, she points out that people who spend their time knitting at least have a scarf to show for it.)

But it is Jan who has had the imagination to dream up a plan to challenge them both: they will hike along the remote and icy Baltic coastline, sleeping in a tent and generally braving the terrible cold. If they stay the course, they will stay together – but if either loses heart and leaves the sandy shore, then they are finished as a couple.

Well, perhaps there are no prizes for guessing whether they have cathartic rows and revelations and quirky serendipitous encounters with unusual people along the way. But the relationship between Jan and Wanda looks very real as they trudge along the vast and freezing seascape, like an ice-cold version of David Lean’s desert. And what does it all add up to? Perhaps not all that much: but it’s a charming and plausible relationship drama featuring people who look as if they might actually be in a relationship.

• It’s Not My Film is at Hull Independent Cinema on 20 March, then tours, as part of the Kinoteka Polish film festival, and on Klassiki from 21 March