A game device is a turn-table adapter having a clip mountable on a case, a shaft passing through one arm of the clip, an operation disk coaxially provided to the shaft at one end thereof, and a press-in disk coaxially provided to the shaft at another end thereof. Another arm of the clip is optionally provided with a bump to be fitted to a hole formed on the case to serve as an element necessary for assembling the game device. A bottom surface of the press-in disk opposite to a press-switch is formed with a bump which engages the press-switch to thereby depress the press-switch.