When producers set out to adapt the megahit South Korean thriller “Squid Game” into a Netflix reality show, they hewed close to the sinister source material.

The cartoony M.C. Escher-like sets are back. So is the barbaric game of “red light, green light.” As are the ubiquitous masked guards and the pine-green tracksuits. Even the $4.56 million prize pot on “Squid Game: The Challenge,” which is said to be the biggest reality TV show prize in history, echoes the original’s 45.6 billion won.