A game system includes a game apparatus, and the game apparatus is
connected with a monitor and a percussion-type controller. When a game
player beats a first beating operation surface or a second beating
operation surface, first operation data is input from the controller to
the game apparatus. Furthermore, when a microphone detects an operation
sound generated at a time that a beating operation is performed, second
operation data including volume data is input from the controller to the
game apparatus. In the game apparatus, when a magnitude of the volume
data is equal to or more than the predetermined threshold value, an
ability value as to an action of the player object to be executed
according to a command indicated by the first operation data is changed
to execute the action.