Play makes you feel uneasy, a kind of Chinese water torture of cinema that is itself deliberately uneasy with what it is trying to do.

Is it an excoriating indictment of Sweden as nanny-but-naive state, a morality play challenging the liberal, excessively tolerant attitude of that country’s citizens to ethnic minorities? Is it saying how an ostensibly head-in-the sand attitude can only end in tears?

Or is it a sly, corrosive polemic about mass consumerism, the endless walls of expensive branded sports-wear and smartphones, targeted at youngsters?

Is it a j’accuse, dramatising children as helpless pawns in the arch-capitalist game? Is it pointing the finger at parents who do not keep a close enough eye on their children?

In fact, you can readily make all of these interpretations from Play, and you may find you have one or two more yourself. A meandering narrative course and an uncertainty about where it is going to go next, make for Play’s powerful, slow-burning impact. Yet it deliberately tries not to look like the thriller it is, accentuating an almost drab cine verité of sociology, as though it were merely people-watching.

Thus it thrives on the everyday - the dull ordinariness of a Stockholm suburb - as it begins quietly in a shopping mall. A gang of teenagers from immigrant families approach two Swedish boys, demanding that one of them show them his smartphone. Without any evidence whatsoever, they accuse him of having stolen a phone belonging to their older brother.

Thus begins another episode in a scam they are trying on across Stockholm, involving a wearisome rigmarole of verbal intimidation, but without physical violence. No adult would reasonably believe their tiresome accusations, but a gullible, polite young fellow would be trusting. These well-dressed, well-fed bullies are typically a little older than their victims, and they speak Swedish.

After securing the phone of another young lad, they force him and his two friends to accompany them as they ride the city trams. On this aimless journey, they intimidate other passengers, they jeer and sneer. In a particularly frightening scene, the phone theft accusation re-surfaces when they are joined by a violent group of  older thugs. Passersby do not intervene because they are unaware of what exactly is going, and scared commuters can’t do much either.

There are other scenes that are not particularly violent but are almost unwatchable, because their almost casual sadism seems convincing and credible. As it unfolds in its creepy way, there are shades of the James Bulger murder about the story. This 2011 movie is apparently based on true events in the second Swedish city of Gothenburg, where a group of boys, aged between 12 and 14, robbed other children of their personal belongings in some forty incidents between 2006 and 2008. The thieves employed role-play - such as the bad cop and good cop scenario- rather than physical violence.

Co-written by director Ruben Östlund, with Erik Hemmensdorff, Play is cinema as visual torture, yes; but it is powerful and thought-provoking, two years on from its release. Play can be seen at the IFI.

Paddy Kehoe