The Mind Flayer is creating an army of Possessed people to invade Earth, and some of you are already under its control... Stay vigilant and make sure it doesn’t attack you or your friends! In Stranger Things: Attack of the Mind Flayer, two teams are going head-to-head: Sane versus Possessed characters. As a Sane character, resist the Mind Flayer’s attacks to win the game. As a Possessed character, make sure all Sane players are Possessed or knocked out by the end of the game.