Provided is a game device which executes a game configured such that a position of a body part of a player is detected, including: a first determination unit for determining whether or not a reference position and a player position information acquired at a first determination time point, which is earlier than a reference time point, satisfy a first criterion; a second determination unit for determining whether or not the reference position and the player position information acquired at a second determination time point, which is later than the first determination time point, satisfy a second criterion; a first processing execution unit for performing processing relating to effects on the game based on a determination result from the first determination unit; and a second processing execution unit for performing processing relating to evaluation of the player based on a determination result from the second determination unit.