To block a drop in interests by eliminating the monotonousness in the process up to the generation of the jackpot game.

Special performance game modes are displayed on a performance image display device 115 according to the establishment of the specified requirements. The special performance modes contain an accumulation display mode and an accumulation special favor mode. The accumulation display mode is so arranged that the progress in the derivation for the display of the accumulation special favor mode is displayed in accumulation showing how a derivation progress value representing it approaches a prescribed achievement upper limit. When the derivation progress value is displayed being accumulated up to the specified achievement upper limit, the accumulation special favor mode is displayed in a characteristic manner different from the accumulation display mode. This can eliminate the monotonousness in the process up to the generation of the jackpot game, thereby blocking a drop in interests.

COPYRIGHT: (C)2008,JPO&INPIT