In a coordinate detection step, a series of coordinate values each of which indicates a position which is on a display screen and is inputted through a pointing device, are detected at intervals of a unit time. Further, an operation state determination step determines whether or not a player is controlling a first object with the pointing device. When the operation state determination step determines that the player is controlling the first object, the selection determination step determines whether or not an input track of the pointing device forms an enclosed area for enclosing a second object based on the series of coordinate values. When the enclosed area has been formed, the first object and the second object are caused to perform predetermined actions.