An electronic gaming machine includes a display in the form of a matrix of rows and columns and a controller configured to conduct a game instance upon receiving a wager via a player input. In conducting each game instance, the controller activates a number of columns on the display based on the wager and controls a display to indicate which columns in the display have been activated. The controller determines if any of the activated columns meets a triggering condition and controls the display to display the activated columns which meet the triggering condition with a modified background. The controller then determines an outcome of the game instance based on whether a predetermined number of activated columns which meet the triggering condition are adjacent one another and makes an award to the player based on the outcome of the instance.