Gaming machine and method for providing a bonus award

A method for allowing a player to play a game on a gaming machine, the gaming machine having a main display and a user interface, the game having a main game and a bonus game, the method comprising the steps of:

• allowing the player to place a wager on the main game;
• playing the main game and randomly establishing a result of the main game;
• awarding the player an award as a function of a paytable if the result of the main game is a win;
• detecting the occurrence of a bonus trigger event during the play of the main game and awarding the player a number of free plays of the main game in response to detecting the occurrence of the bonus trigger event;
• playing the free plays of the main game;
• detecting an appearance of a trigger bonus symbol during the free plays of the main game and randomly selecting one unique bonus symbol of a set of unique bonus symbols;
• displaying an animation in place of the appearance of the trigger bonus symbol;
• displaying the randomly selected one of a set of bonus symbols in place of the animation;
• and
• awarding the player a bonus award if all of the unique bonus symbols are selected during the free plays of the main game.