The core cast for Netflix’s mega-hit survival drama Squid Game stopped by The Tonight Show on Wednesday, where they reckoned with the show’s massive success.

Joined by Lee Jung-jae, Park Hae-soo, Wi Ha-joon, and Jung Ho-yeon, Fallon asked them how they have been dealing with the immense success of the show, with Hae-soo admitting he only just heard that it’s the No. 1 Netflix show in 90 different countries. "I definitely think the Korean children’s games are part of the appeal," said Wi Ha-joon, who portrays Hwang Jun-ho on the show. "That can be very original, refreshing, and also shocking at the same time to the global viewers.” Another factor, he suggested, is the show’s “raw” depiction of greed and human nature.

Fallon also brought out the very creepy red light, green light doll, and noted that its design was based around a character from a Korean textbook. Lee Jung-jae added that for as much inspiration the show took from the original games, there was also plenty of improvisation on the set, too.

“There was definitely a lot of improv during the shoots," said Jung-jae, who noted a scene where he bumped into another character and made her drop her coffee. "Typically, you would just pick it up and hand it to her but I noticed the straw on the ground so I improvised and tried to stick the straw back into the cup. I tried to do it multiple times. That made Ho-yeon crack up so hard that she couldn’t lift her head up."

The actors were also subjected to a series of Fallon’s own take on schoolyard games, although thankfully this time around they didn’t have to risk their lives.

Check out clips from the Squid Game cast’s Tonight Show appearance above.