An example of a game device accepts inputs from a plurality of players to allow a game to progress. First, the game device accepts a first rhythm input by a first player. A model rhythm is generated and presented based on the first rhythm input. The game device accepts a second rhythm input by a second player. Then, the game device evaluates the second rhythm input using as a reference the model rhythm. Thus, by generating a model rhythm based on a rhythm which is input by a player, it is possible to provide a game with a high playability having an increased degree of freedom for the model rhythm.