The characters from The Good Place would come at Squid Game with a unique advantage: they know what happens after death so would have less reason to be afraid (other than Chidi). Of course, some powers the characters have in the afterlife would be useless in Squid Game because their powers do not work on Earth.
The characters would likely have very different approaches and use different tactics in Squid Game - some would thrive because of their love of human suffering (like Oh Il-nam and Jang Deok-su) and others would have an approach like Seong Gi-hun, trying to uphold some sense of ethics throughout. But, who would come out on top?
Derek
As he is created by Janet and is far removed from human understanding, Derek remains an enigma in The Good Place. By the end of the series, he has been reset so many times that he has become at one with the Universe, but for most of the series Derek is like a baby - he does not know or understand things yet.
This puts Derek at a major disadvantage in Squid Game. He would almost certainly be eliminated in the first round: Red Light, Green Light.
Jason Mendoza
Jason's athleticism would be an advantage in Squid Game - he would most likely breeze through the first round because he can run fast. However, although Jason does grow and develop in The Good Place, his low level of intelligence and childlike mind remains throughout, which would definitely hinder his prospects.
Undoubtedly, Jason would opt for the "funnest" honeycomb shape (the umbrella) but would lack the focus, quick thinking, and dexterity to successfully complete the task, getting himself eliminated in the second round.
Trevor
Trevor the demon's love of torturing humans and general villainous nature would come in handy in Squid Game. However, he is one of the most unlikable characters in The Good Place and is always intentionally saying provocative (and often politically incorrect) things to try and wind the humans up.
Although he would take pleasure in participating in the games, Trevor would definitely rub the other contestants up the wrong way, making him a prime target in the fight that breaks out in the dorm.
Vicky
Similar to Trevor, Vicky's love of causing human suffering would make her right at home in Squid Game. Although she would love watching the humans squirm, she would undoubtedly hate not being in charge and would try and suggest improvements to the guards or strike a wager to become one of them.
Again, her behavior would not make her popular among her fellow competitors, meaning that when the fight breaks out her fellow competitors would surely take the opportunity to eliminate her.
Chidi Anagonye
Squid Game would be Chidi's absolute worst nightmare and would probably feel even more torturous for him than The Bad Place. He would constantly be having to make quick decisions and weigh up ethical quandaries, providing fans with more funny, nerdy Chidi moments.
However, Chidi is also highly intelligent and "surprisingly ripped" so he would most likely make it through the first couple of rounds (even though choosing a shape in the Honeycomb round would be the most difficult thing he'd ever done). However, Chidi's moral com would not allow him to kill someone else to save himself, meaning he would be eliminated in the Tug of War.
Michael
Although Michael would experience some existential dread in Squid Game, he really has the potential to go all the way: he knows everything about the universe, has caused human suffering (as a demon), and has spent a lot of time learning about ethics.
Nonetheless, Michael loves his friends more than anything and would absolutely sacrifice himself before seeing them eliminated, much like when he heartbreakingly sacrificed himself on the way to meet Judge Gen. Michael in one of The Good Place's saddest scenes. Michael would therefore intentionally lose the Marbles round, in order to save one of his friends.
Shawn
Although Shawn would be unpopular with his competitors (as he is literally evil), his drive to win and brutal tactics would take him far in Squid Game. He would have no issue taking others out to ensure his own progression and would even take enjoyment in watching the humans around him dropping like flies.
However, Shawn can be lazy and his main motivation would be, and as it has always been, beating Michael. Once Michael is eliminated, Shawn would probably lose interest, get lazy, and be eliminated shortly afterward.
Tahani Al-Jamil
Although Tahani might not be popular among her other contestants because of her constant name-dropping and bragging, she is highly athletic, intelligent, and, above all, competitive. Tahani would really want to win, almost certainly more for the title than the money (which she wouldn't really need).
Unfortunately for her, Tahani's love of coming first would also be her downfall. Undoubtedly, she would choose number one in Glass Hopscotch, giving her no chance of making it through the round (although she would certainly try to talk her way out of it).
Janet
In the afterlife, Janet is omniscient. She knows everything there is to know about the universe and can conjure objects out of thin air (although she cannot do this on Earth). Her limitless knowledge, sturdy, manufactured body, and fearlessness would make Janet unbeatable in Squid Game.
Although Janet could certainly win if she wanted to, she is unafraid of 'death' and her love for her human friends would mean she would never hurt them to get ahead. In an emotional and heartwarming Good Place moment, Janet would destroy herself to save her friend in the final round.
Eleanor Shellstrop
Eleanor's haphazard nature would have her playing in a similar way to Seong Gi-Hun: she would form a group of allies, take things as they come, and be heavily reliant on luck. She would learn from experience, and adapt her playing style as required throughout. Eleanor would not necessarily be the most obvious person to bet on, making her highly underestimated.
Her quick reactions, adaptability, and positive outlook would take Eleanor to the very end, along with the and sacrifices of her friends along the way of course.