A gaming machine provides a spinning reel game having a base game, from which a hold and spin feature game may be triggered when a determined number of configurable symbols are displayed in a base game outcome. When the feature game is triggered, the configurable symbols may be held in place. The player may be provided one or more spins during the feature game in which to collect additional configurable symbols. Any additional configurable symbols may be retained on the display during subsequent spins until the feature game is completed. A trigger symbol, which may or may not be a configurable symbol, may cause reel expansion. The reel expansion may involve adding a row or a column. In some examples, the trigger symbol also may alter the value of at least some configurable symbols. For example, the trigger symbol may cause the value of a configurable symbol to increment.