The game apparatus shoots a moving object from a predetermined weapon object and moves the moving object in a three-dimensional space in a case where an input from an input device is received. At least one of the size, the shape, and the number of a contact determination area defined for the moving object is changed in accordance with a distance over which the moving object moves in the three-dimensional space. The game apparatus determines whether or not the contact determination area defined for the moving object contacts a contact determination area defined for a target object. A predetermined game process is performed when the determination result of a contact determination step is positive.