Game apparatus and storage medium having stored thereon game program

Whether or not an angular velocity detected by an angular velocity sensor is used for a game process is determined, and a difficulty level of a game to be subjected to a game process is set so as to vary depending on whether the angular velocity is determined to be used or the angular velocity is determined not to be used. When the angular velocity is determined not to be used, a process of specifying a motion direction of an input device is performed by using acceleration detected by an acceleration sensor, whereas when the angular velocity is determined to be used, at least a part of the process of specifying the motion of the input device is performed by using the angular velocity detected by the angular velocity sensor. Accordingly, based on the specified motion direction, the game process is performed while the set difficulty level is applied.