Squid Game The Challenge: It felt like it was real, says contestant

Players try to run for the line without being caught moving by the swivelling doll

Mysterious masked guards in pink boiler suits, a singing giant doll and a life-changing sum of money... it can only mean the return of Squid Game.

The Netflix hit has come back to our screens, but this time with a reality game show spin-off seeing 456 real players battle it out for a $4.56m (£3.66m) prize fund - one of the biggest cash prizes in TV history.

The gigantic set is the first thing that hits you about Squid Game: The Challenge, before the show kicks off with hundreds of hopefuls in green tracksuits trying to cross a line without being seen to move by a 13.7ft (4.2m) doll furiously swivelling her neck.

"It felt like it was real - it didn't feel like you were in a fictional place," contestant Lorenzo Nobilio, 26, told BBC News.

Only this time it was radio-controlled exploding dye taking out stumbling players in Red Light, Green Light, and not a fatal bullet on the spot.

Describing it as the physically hardest game on the show, the London-based Italian said: "I made it past the line in seven hours, that was a very long time, but it's called Squid Game: The Challenge, it's not an all-inclusive holiday in the Canary Islands."

Seven hours? Yes, you heard right. With the stakes high, a team of adjudicators - trained lawyers - had been examining footage frame by frame to spot who needed to be kicked out.

Contestant Lorenzo Nobilio, right, said the show felt real

The show made headlines earlier this year, when people received medical treatment during filming and contestants complained about the cold conditions amid freezing UK weather.

"It was no worse than many unscripted shows, if you look at Survivor or SAS: Who Dares Wins," claimed executive producer Stephen Lambert of Studio Lambert, the production company also behind hit game show The Traitors.

"When you are giving away a huge prize, it was always clear it was going to be a tough show to take part in."

That huge prize attracted applications from 81,000 people from around the globe, before they were whittled down to 456 seemingly normal people - unlike fellow Netflix reality competition show Physical: 100, which gathered a hundred South Korean competitors at peak fitness, including national athletes and bodybuilders.

Squid Game: The Challenge players - mostly American - ranged from a mother and son duo to the oldest at the age of 69. The ones highlighted in the very long series with interviews are mostly people you can warm to, that's if they're not being suddenly eliminated from the show.

"We were interested in the games as a test of human nature, so we wanted the widest possible variety of people," explained one of the show's other executive producers, John Hay from production company The Garden.

When not playing original games from the series like intricately cutting out umbrella-shaped honeycomb wafers with a needle and new games like battleships, contestants were fully immersed in the Squid Game universe.

No phones, confined to a prison-style dormitory, sleeping on five-bed-high bunk beds, and surviving on rationed food served by those menacing guards.

"My strategy was if I keep well fed [by hiding second helpings under his duvet], I'll actually be stronger than the others and maybe win," Nobilio said, who worked in private equity before joining the show.

The Big Brother-like living space also provided ample time for alliances to form. And in a new addition, players are also given chances to eliminate others, as part of the producers' aim to create drama and reveal players' characters between games.

Between games, players were confined to a windowless dormitory, where they slept in bunk beds

But what about the criticism from some Squid Game fans - who are mostly waiting for the second season of the drama confirmed last year - that a real life version flies in the face of show's message? The drama's creator Hwang Dong-hyuk had previously said the story "was an allegory or fable about modern capitalist society".

In the original drama, Netflix's most watched series, debt-ridden South Korean contestants compete in a series of children's games for a huge cash prize won only by the last surviving player.

Executive producer Hay points out that this show is flipped so it's driven by opportunity rather than need.

"We are giving them the most enormous opportunity and it turns out that's as strong as a motivation and story."

A point lost on critics, who all flagged the contradiction, but have mostly given the show the thumbs up.

The Guardian called it the most gripping reality TV since The Traitors, giving it a four-star review. Also giving it four stars, the Radio Times concluded that it was "more intense than the hit show".

Meanwhile, the Evening Standard preferred to call it a "shoddy knock-off", awarding it just two stars. The i giving it one star called it a "cynical attempt to regenerate the viewing figures Squid Game earned".

Producers are waiting to see if it indeed does win over audiences.

"It's amazing to make something which comes off the back of a show as popular as Squid Game," Hay adds. "That's the ultimate in head starts."

Squid Game: The Challenge is available on Netflix from Wednesday 22 November.

The Dalgona Candy from the original makes a return in Squid Game: The Challenge