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.