Johannes Nyholm’s film is a strange, self-aware little psycho horror about grief: the title is taken from a bizarre (and genuine) Swedish nursery rhyme, Our Rooster Is Dead, played here on a musical box belonging to a little girl: “Vår tupp är död, vår tupp är död, Han kan inte sjunga koko-di koko-da!” (“Our rooster’s dead, our rooster’s dead, He’ll no longer sing koko-di, koko-da!”) Her musical box has three weird figures drawn on it: a dapper old gent in a straw boater, a young woman with a dog on a lead, and a brutish Goliath of a man carrying a dead dog (oddly, no roosters, dead or alive). It’s not clear whether these figures are accurate, like the rhyme, or made up for the film.

The lead characters are a couple, Tobias (Leif Edlund) and Elin (Ylva Gallon), who in the time-honoured manner of horror films are dealing with a terrible private tragedy. They go on a camping trip into the woods, and if you thought their anguish wouldn’t come back to haunt them in supernatural form, you would be quite wrong. They are set upon by the three nightmare figures from their daughter’s musical box come to life, and then set upon again and again, in a horrifying time loop from which desperate and perhaps illusory lessons are there to be learned, in the style of Bill Murray in Groundhog Day. And the action is interspersed with a weird magic lantern show (whose mythic content may be entirely invented), which also appears to have a significance for the unhappy couple.

It’s an interesting film whose contrivances aren’t as fiercely alive as they could have been, but it delivers some shocks and scares of a certain sort, with vague echoes of Ruben Östlund or Michael Haneke. It works as a parable for what happens to grief when it is left unexorcised and unexpressed.

• Koko-di Koko-da is released on 7 September on BFI Player.