Game system, program, and information storage medium

A game system including: a music reproduction section which reproduces given music data stored in a storage section; a display control section which performs display control of changing a relative positional relationship among a direction mark which directs an operation to be performed by a player using an operation section, a special direction mark for the second game and a reference mark for timing judgment of the operation in association with a reproduction state of the music data to cause the direction mark and the reference mark to come closer; a timing acquisition section which acquires operation timing when the player operates the operation section for the direction mark; and a game calculation section which performs calculation processing of a first game of comparing the acquired operation timing with timing criteria and calculation processing of a second game differing from the first game based on operation information of the operation section for the special direction mark.