Netflix has released a teaser for the second season of Squid Game, the smash-hit South Korean survival drama series. A letter from creator, writer, director and executive producer Hwang Dong-Hyuk also revealed which characters will return in Season 2 of the popular show.

“Red light... GREENLIGHT!” reads the message, accompanied by a quick animation of the enormous animatronic doll that stars prominently in the Squid Game pilot.

After the phenomenal popularity of the Korean series on Netflix, the second season of Squid Game was almost inevitable. The first season was by far the most popular TV show on Netflix, with 1.65 billion hours of viewing in the first four weeks of its release in September last year.

The smash-hit series centres on a competition in which 456 people, all of whom are in serious financial need, risk their lives by playing a series of deadly children’s games in the hopes of winning a fortune.

Netflix has also released a letter from the Squid Game creator Hwang Dong-Hyuk. “It took 12 years to bring the first season of ‘Squid Game’ to life last year. But it took 12 days for ‘Squid Game’ to become the most popular Netflix series ever,” read the statement from Hwang.

Hwang went on to tease a bit of the story for the second season, indicating that both protagonist Seong Gi-hun (Lee Jung-jae) and masked adversary the Front Man (Lee Byung-hun) will return.

He has hinted at the return of a fan favourite cameo – Gong Yoo, who played the mysterious recruiter who pulls desperate people into the game using the traditional Korean card-flipping game of ddakji.

Hwang also revealed that the boyfriend of Young-hee, the enormous killer animatronic doll who demonstrates to spectators how dangerous the game is, will be introduced.

“Join us once more for a whole new round,” the 51-year-old said.

In January, Netflix co-CEO Ted Sarandos had officially confirmed that more episodes of Squid Game were on the way.