A gaming machine, method, and non-transitory computer readable storage medium are disclosed, which permit a player to play a base game and a feature game that may be triggered or initiated through play of the base game. During play of the feature game, the gaming machine holds each instance of a feature trigger symbol in its respective feature game display position and, if a feature game has remaining spins, spins/respins reels to obtain replacement symbols for each feature game display position without the feature trigger symbol. If a newly-presented feature trigger symbol includes one or more directional components, the gaming machine propagates the new-presented feature trigger symbol in a direction or directions indicated by the one or more directional components.