Now, in Squid Game: The Challenge, those games – or most of them – have been recreated on huge sets in the UK with 456 contestants (mostly from the US and the UK) competing against each other to win a life-changing – and record-breaking for a gameshow – prize of $4.56m (£3.61m). SGTC brilliantly reproduces the structure and aesthetic of the source show and also adds a few twists of its own. It makes for very compelling viewing but also raises questions about what constitutes entertainment.

Obviously, SGTC has no lethal element but it turns out, unsurprisingly, that people are prepared to be pretty ruthless and unpleasant in order to get their hands on $4.56m. So-called "alliances" are betrayed, Machiavellian scheming is rewarded, and we might yet see familial relationships put to the test. In addition, it has been reported that two contestants are now threatening legal action over alleged injuries sustained during filming, although a spokesperson for the show said: "No lawsuit has been filed by any of the Squid Game contestants. We take the welfare of our contestants extremely seriously."

Writing in Psychology Today, psychologist Dr Pamela Rutledge even suggests that the show is "ethically questionable", arguing that it "turns the original series, where violence was a call to action against inequality" – ie where the violence was a metaphor in a drama about poverty and social disparity – into "a vehicle that promotes the opposite: a 'game' among 'real people' where ruthlessness and lack of empathy are essential to a big payout". Should we feel bad about watching contestants suffering and being humiliated on a global platform?   

In The Age of Static, his book about how TV has affected society, critic Phil Harrison wrote of the first British season of Big Brother, a show to which SGTC has been compared: "It became clear that at its best, this stuff had what it took to compete with, and possibly even surpass, scripted fiction." He feels the same about SGTC.

'An inversion of what the drama stood for’

"It is horribly entertaining and I devoured it," Harrison told BBC Culture. "But I've also watched with a certain amount of guilt. I think the problem, such as it is, is that the drama version is such a bitterly acute satire of the ruthlessness of late capitalism, whereas, played out for real, it loses the satirical beats and becomes the thing the drama railed against.

"I talk about the 'last man standing' trope in my book – the notion [promoted by reality TV series] that sharp-elbowed competitiveness is the only feasible route to personal fulfilment – and how it feels very symbolic of our era in terms of how many people lose as opposed to how many eventually win. You see it in shows like The Apprentice and Big Brother and films like The Hunger Games too. This feels like the ultimate expression of it, which is ironic because it’s an inversion of what I assume the intention of the drama was.

"There were a couple of moments [in the first batch of episodes] which I found genuinely quite hard to watch, and I was quite concerned about the well-being of the people involved. But that extremity is, I suspect, a feature not a bug – it’s one of the reasons it’s so compelling."

So are we all sadists, revelling in human suffering while watching from the safety of our sofa? Not necessarily, says Dr Sandra Wheatley, a social psychologist for Potent, and a chartered member of the British Psychological Society, who believes that we’re sucked into watching a show like Squid Game: The Challenge for less obviously malign reasons – because of a desire to be part of the cultural conversation.

"People loved Squid Game and this is building on that show's reputation. It’s new and exciting and a little bit risky," Wheatley tells BBC Culture.

"It goes viral because of word of mouth, and then people are frightened of being left out. They like to keep up with things, to feel part of the herd. When you're at the bus stop or the queue in the canteen or in the pub and somebody says 'Did you see Squid Game: The Challenge?' and if you haven’t they’ll be like 'oh my God, you've got to watch it'.

"We like to be able to talk about things we have in common. It gives us some social binding."

And the makers of the show point out that all the contestants wanted to be there, and had their suitability for taking part checked during the selection process.

John Hay, CEO of The Garden, one of the two British production companies behind the show, tells BBC Culture: "Hopefully people are watching while understanding that we're exercising the proper duty of care around all these people, and that what you’re seeing is the pressure of a game. We were doing everything we could and should to make sure that the pressure was at a tolerable limit."

Of Spencer, the contestant reduced to tears in the second episode, he says: "There's been follow-up with Spencer right the way through to transmission to make sure he was happy with the show."

Stephen Lambert, boss of Studio Lambert, the other production company behind it, tells BBC Culture that what actually keeps viewers hitting the Next Episode button is "finding narratives that the audience will be hooked by and stopping at the point where you just want to find out what happens next".

And finding those narratives, when the programme makers did not know which contestants will prevail, was one of the show’s biggest challenges.

"The show breaks all the rules of unscripted television – any television really. You can’t engage an audience unless you’re concentrating on a relatively small number of characters and we were starting off with 456," says Lambert. "So the challenge from a filming point of view but particularly from an editing point of view was to work out who to concentrate on. The trouble was that you can’t film everybody at once – even though we had a lot of cameras. So we were always having to concentrate our efforts on a certain number, and very often the people that we thought were interesting and we were following their narrative, they were suddenly eliminated.”

Stephen Harcourt, Studio Lambert's creative director, even suggests that there is actually a lot of kindness on display. "I think you would expect a lot of people to be clambering over others and cutthroat, and while there are moments where people are cutthroat, deep down people are essentially good and kind and collaborative and social and thoughtful."

Perhaps we'll see all that collaboration and helpfulness in the second tranche of episodes.

The next four episodes of Squid Game: The Challenge are released on Netflix on 29 November, and the finale is released on 6 December