To provide a game system enhancing a game characteristic using an image for instructing operation timing.

This game system is provided with operating buttons 7 that can be operated by a player; storage devices 15, 16 and 17 stored with data defining the operation timing of the operating buttons 7 during a game; an image description control device 11 for displaying an image for instructing the operation timing of the operating buttons 7 during the game, on a screen of a monitor 3; and a CPU 10 for evaluating the operation timing of the operating buttons 7 of the player. The changeover is made between a first mode of making the image description control device 11 instruct all the operation timings stored in the storage devices 15, 16 and 17 as an object to be operated by the player, and a second mode of making the image description control device 11 instruct only a part of the operation timings stored in the storage devices 15, 16 and 17 as the object to be operated by the player.