In a game system 1, instruction marks corresponding to sounds constituting part of a music number are displayed on a monitor 3, and a game player plays a game by operating a signal generating device 5 by at least one of a hitting motion and a swinging motion at specified timings based on the displayed instruction marks. The game system 1 is provided with a display means for successively renewably displaying the instruction marks on a display screen of the monitor 3, a signal generator provided in the signal generating device 5 for generating a signal when the signal generating device is operated by the above motion, an evaluating means for evaluating a game result based on a generation timing of the signal, and a sound generating means for outputting at least the background sounds.