Showdown Spins is a very special method where the free spins bonus round proceeds in two distinct phases: 'Phase 1: Collection' and 'Phase 2: Showdown'.
The core of this feature is to first collect as many powerful 'assets' (wilds, multipliers, etc.) as possible for the bonus in a manner similar to 'Hold and Respin', and then to unleash all of these collected assets during the final few decisive 'Showdown Spins' to create massive high payouts.