1. A computer readable recording medium storing a game program which causes a computer of a game apparatus to execute the following steps, the game apparatus comprising an input device of detecting a position specified by a player on an input surface: a storing step of storing input positions detected by the input device at predetermined time intervals, in order of detection, into a memory of the game apparatus; a trail vector calculating step of calculating a trail vector indicating at least a portion of a trail drawn by the player on the input surface, from the input positions; a reference vector calculating step of calculating a reference vector whose starting point is a predetermined position on the input surface and whose ending point is a position determined by the trail vector; an action determining step of determining an action of a player's character based on an angle between the trail vector and the reference vector; and a display control step of causing a display device to display a state of the player's character performing the determined action.