Disclosed is a gaming system including a gaming machine. In response to a triggering event, the gaming system initiates play of a feature game including a plurality of standard symbols and value symbols, the value symbols being associated with one or more values. Value symbols adjacent to one another are combined into a larger composite symbol and held in place on a display device, the standard symbols then replaced with replacement symbols randomly selected from the standard and value symbols. When the replacement symbols include another value symbol adjacent to the composite symbol, the new value symbol is also combined with the composite symbol, increasing its size. At the conclusion of the feature game, a reel associated with the composite symbol is displayed and spun to select an award from a set of possible awards based on the size of the composite symbol.