A game device causes a display device to display an image in which plural marks correlated with step panels to be stepped on by a player move to reach a base line, and the game device, when a step panel is stepped on, classifies the degree of accuracy of this operation as one of plural classes based on a time at which a mark corresponding to this step panel reaches the base line, a time at which this step panel was stepped on, and plural thresholds. The game device counts the number of accurate operations, to cause the display device to display the number in a color corresponding to the lowest accurate operation class corresponding to the counted accurate operations.