A slot machine 10 comprises a display 20 having 3 rows by X columns (X being an integer of 5 or greater) of display regions, and a controller 50. Controller 50, in the event that bonus symbols 70, 71, and 72 are displayed in the (X-2) display regions in the center row of the 3 rows, excepting both side columns, starts a bonus game on the display. In the bonus game, the controller causes a prescribed character 66 to move on the display regions surrounding the (X-2) bonus symbols, and thereafter, selects a symbol by causing character 66 to perform a prescribed action on one of the display regions. Based on the type of the selected symbol, the content of the bonus awarded to the player is determined.