A massive earthquake hits Seoul – though the images suggest it has gone well beyond - leaving one huge block, standing alone amidst the rubble and destruction of the rest of the city.

What’s presented by director Tae-hwa Eom and co-writers Lee Shin-ji and Kim Soong-nyung are the attempts of the community to pull together until emergency services arrive – though there’s little indication that there are any left. This entails pulling together resources, choosing a leader and some tough decision as resources dwindle. The latter is what to do with the ‘outsiders’ later called cockroaches.

So there isn’t very much here in this Lord of the Flies tale of survival and factions that hasn’t been done before. However the main cast is kept down to three with a few peripherals to tell the story, which is interspersed with flashbacks to flesh out the story and characters.

So there’s sensible couple Min-sung (Park Seo-joon) and his wife Myung-hwa (Park Bo-young) who look to be practical and even take in a mother and son, despite lack of food. The there’s the not that bright but viciously cunning Yeong-tak (Lee Byung-hun) who after a slow start become the leader, elected by the residents, and sets about some controversial policy ideas while keeping a grip on power by manipulating many of those around him.

What follows is a diet of misery and violence as the situation gets worse. And as is so often in broken societies scapegoats are created to appease the followers and retain power and with that the process of dehumanisation.
As familiar as all this is, it is very well done and keeps the viewer engaged for the duration. And the filmmakers do provide a shock or two.

The three main protagonists are excellent all believable with Bo-young creating some empathy for Myun-hwa as she sticks to her principles. Seo-joon is not so sympathetic but understandable as Min-sung starts to crumble. Tak is intriguing and is a classic rise through the ranks to power character, Byung-hun creating a nasty piece of work without overdoing it.

Technically the film looks fine featuring some solid effects work, the colours and hues are the customary blue/grey of dystopia with little in the way of bright light.

Concrete Utopia is now available on digital platforms in the UK and Ireland.