A soccer game apparatus includes a game processor, and the game processor allows at least a character of a soccer ball to be displayed on a television monitor screen. An signal outputting device is attached to a player's leg, and when the player moves the leg, an acceleration correlation signal correlated with an acceleration as of that time is output from the signal outputting device. Upon receipt of the acceleration correlation signal by an infrared signal, for example, the game processor causes a change to the character of the soccer ball displayed on the screen.