Patent ID: 8162754

Claim:
A game device, comprising: a detection mat, located on a surface, that detects a pressure onto the detection mat and a position of the pressure in the detection mat; a controller that is detachably attached to the detection mat; an acquiring unit that acquires, via the controller, an operation instruction made by a stepping motion of a player on the detection mat, based on the detected pressure and the detected position of the pressure; a controller detection unit that detects a position of the controller; a measuring unit that measures an amount of displacement of the detection mat relative to the surface in a predetermined direction, based on the detected position of the controller, the predetermined direction being parallel to the surface, wherein the measuring unit, in measuring an amount of displacement of the detection mat, acquires a first position of the controller from the controller detection unit, acquires an indication of the stepping motion of the player on the detection mat, and acquires a second position of the controller from the controller detection unit, the amount of displacement of the detection mat relative to the surface in the predetermined direction being a function of the first and second positions of the controller; and an output control unit that outputs advisory information in a case where the measured amount of displacement in the predetermined direction exceeds a reference displacement value.