Continuity mistake: In Gi-hun's hand close-up shot, he's holding the tooth by the tooth itself, but when it cuts to a medium shot of his face, we can see he's holding it by the metal wire now. (00:22:34)
Trivia: They keep guessing the next game, however clues are hiding in plain sight. The illustrations on the dormitory walls depict all the games, from "Red Light, Green Light" to the final match of Squid Game.