The game unit has four large buttons, one each of the colors red, blue, green, and yellow. The unit lights these buttons in a sequence, playing a tone for each button; the player must press the buttons in the same sequence. The sequence begins with a single button chosen randomly, and adds another randomly-chosen button to the end of the sequence each time the player follows it successfully. Gameplay ends when the player makes a mistake or when the player wins (by matching the pattern for a predetermined number of tones).