As shown in (A) of FIG. 22, a batter is displayed on the display 2. When the user makes a gesture of paper with their right hand, the portable electronic apparatus 1 recognizes the gesture on the basis of an image from the infrared camera 4, and projects an image of a ball onto the right hand of the user by using the projector 8. Next, when the user makes a gesture of swinging their right hand, the image of the ball projected on the right hand of the user disappears, and the ball appears from the right edge of the display 2 and moves in the leftward direction of the screen ((B) of FIG. 22). When the user presses the input button 6B at the timing at which the ball reaches a predetermined range of the batter, the batter hits back the ball ((C) of FIG. 22). The hit-back ball moves in the rightward direction of the screen. The user makes a gesture of rock at predetermined timing (timing at which the hit-back ball reaches the right hand) after the ball reaches the right edge of the display 2. Accordingly, an image of the ball is projected onto the right hand of the user as if the user caught the hit-back ball ((D) of FIG. 22). At that time, characters OUT indicating that the user is successful in catching the ball may be displayed on the display 2, and a sound may be outputted, or the portable electronic apparatus 1 may vibrate. The portable electronic apparatus 1 may recognize the position of the right hand of the user (a position on a plane parallel to the right side surface of the portable electronic apparatus, and/or a position in a direction perpendicular to the right side surface) on the basis of an image from the infrared camera 4 or a distance measured by the distance measuring sensor 5, and may project an image of the ball onto the right hand of the user in accordance with a result of the recognition. When the user does not make a gesture of rock at the above-described predetermined timing or the timing at which the gesture of rock is made deviates from the above-described predetermined timing, the user fails in catching the ball, and the image of the ball as shown in (D) of FIG. 22 is not projected onto the right hand. For example, an image different from the ball may be projected onto the right hand, or characters ERROR or HIT may be displayed on the display 2. When a gesture made by the user cannot be recognized with the infrared camera 4, the same process as described above may be performed by detecting movement of the hand with the distance measuring sensor 5