A conventional game program involves the risk of the player losing interest in the game. A computer-readable program product which enables a beginner player to sufficiently enjoy interest in a game is provided. A character to be subjected to ring customization is selected. If a technical ring is selected as a ring type after the subject has been determined to be change of a ring type, an ally character makes attacks only when the player has performed operation input with a rotary bar situated in any of timing areas. When a gamble ring is selected as the ring type, only one timing area is available. In a case where a practice ring is selected as the ring type, determination of operation input timing is continuously made in all the remaining timing areas even when the operation input has been performed with the rotary bar not situated in any timing area.