A processor of a gaming machine receives input via an player input device that selects a denomination for a play of a base game and displays symbols of a base game outcome at base game display positions of a display device. The processor randomly assigns to a configurable symbol of the base game outcome a prize that is based on the selected denomination and triggers a play of a feature game based on the play of the base game. For the play of the feature game, the processor retains each configurable symbol of the base game outcome at a corresponding feature game display position of the display device, and for each feature game display position without a configurable symbol, selects and displays a replacement symbol. The processor determines a feature game award based on a sum of prizes for each configurable symbol displayed at its feature game display position.