Stacked Symbols
On every spin, one of the regular symbols will randomly be chosen to be super-stacked on all five reels. During Free Spins these random Super Stacks are even longer and also mystery symbols that are also in play, which reveal a random paying symbol after the spin.
After a spin, whenever a reel contains a full stack of the same symbol it can switch places with other full stacks of different symbols to help create or improve wins.