Missile Defence is a clone of Missile Command. The gameplay is the same. The player has to defend six cities from ballistic missiles that comes from the sky. To his help the player has three batteries mounted at the bottom of the screen, which are controlled by moving a crosshair across the screen. However, when using a joystick to control the player can only use the center battery. In addition to the missiles there is planes flying across the screen, dropping more missiles. When all the cities are destroyed, the game is over.