They're Coming is a zombie survival game. You must move your survivors through several locations to the rescue station while fighting off your opponent's zombies.
Depending on the version of the game, players have two modes of play. In the "Single Pack" or "Travel Edition" of the game, one player take on the role of the survivors and the other the zombies; in the "Standard" or "Two Pack" version, both players take turns being survivors and zombies in a round of play. Survivors draw from a survivor supply deck and must navigate locations (chosen by the opponent) that are infested with zombies (which are played from the opponent's zombie deck).
In the Standard game, the player who gets the most uninfected survivors to the rescue station wins. Non-standard games can be played by increasing the number of locations that survivors must pass through and/or by reducing the number of survivors to start the game.