To enhance thrill of expectation and sense of fear of the player for possible continued duration of a specific game.

Condition to regulate the continued duration of a specific game accompanying a big bonus game (BB game) is determined in advance by lot. After elapse of a defined time from the start of the BB game, or more particularly at a time when possibility of closure of the game owing to various conditions occurs, the machine informs the player whether continuation of the game is possible or not.