Provided is a game system including: a first game processing means for placing, based on an operation by a player, an object in a virtual space of the player, and executing a first game that progresses by using the object; a second game processing means for causing an enemy character to appear in the virtual space, and executing a second game that causes the enemy character and a player character, which have satisfied a given condition, to fight a battle; and a game management means for executing processing for permitting the player to perform an operation relating to the second game when it is judged that the given condition has been established in the virtual space during the execution of the first game, and reflecting a result of the battle in the second game in a parameter to be used in the first game.