Abstract: There are provided a gaming machine and method that utilize game-logic circuitry and a presentation assembly configured to present a plurality of symbol-bearing base reels, a base array, and a plurality of persistent elements. The plurality of base reels are spun and stopped to land symbols from the base reels in the base array. In response to the landed symbols including at least one accumulation symbol, an animation of addition of the accumulation symbol to one of the plurality of persistent elements is presented. An animation of the accumulation symbol being added to one or more of the plurality of persistent elements in a cascading fashion may also be presented. A random determination whether or not to trigger one or more game features is made. If the determination is to trigger the one or more game features, the one or more game features are implemented via the game-logic circuitry and the presentation assembly.