A gaming machine has a display and a game controller arranged to control images of symbols displayed on the display device. The game controller is arranged to play a game in which at least one random event is caused to be displayed on the display device. If a predefined winning event occurs, the machine awards a prize to a player. When a trigger condition occurs in a base game of the game, a bonus game feature is awarded comprising a series of bonus games. If a particular special symbol outcome occurs during any of the bonus games, the particular special symbol outcome is collected towards a jackpot prize awarding event.