To provide a simulation game for Pachinko game machines visibly displaying a moving route of a ball picture passing on a board image as an image.

This game apparatus 1 is provided with an operation input device 20 for inputting a game operation, a display device 30 for displaying the image, and an image processing means 46 allowing the display device to display a game screen where the ball image BP moves on the board image 61 repeating a contact with a plurality of obstacle images; is further provided with a ball position deriving means 71 deriving the ball position, or an ever-changing position of the ball image, on the board image, and a ball trajectory deriving means 79d deriving a ball trajectory, or the trajectory of passing of the ball image, based on the ball positions; and the image processing means 46 is so constituted as to display the ball image based on the ball positions and display a trajectory image for visualizing the ball trajectory on the game screen.