A game system capable of determining, and reflecting in games contents, nervousness of a player due to fear or the like is provided. A game device main body 110 performs the game processing based on an operation of the player on the first controller 121, and calculates, in a scene of a game, a nervousness parameter indicating the degree of nervousness of the player in the scene based on an operation of the player on the first controller 121. Specifically, the game device main body 110 calculates the nervousness parameter in such a way that the degree of nervousness increases according to the number of operations of the player on the first controller 121 that are irrelevant to the progress of the game, or the like, and causes the nervousness parameter to be reflected in the game processing.