The Hot Spot feature activates randomly in the base game, with an electrified section shown in the middle reels, landing 4 matching fighters in this section locks them in place, converts them to wilds and triggers re-spin of the reels.
Any further matching symbols that land on the reels during the re-spin are also then converted into wilds.
The free spins round is triggered by landing a full strip of matching fighter symbols on reels 1 and 6, you are then granted 5 spins of the reels where any of these 2 fighters that land in view are held in place until all of the spins have been used.
There are a number of special symbols which can add multipliers and extra symbols horizontally and diagonally to the reels also.
When all of the spins are finished the fighter with the highest score is then converted across all of these symbols and the win is paid.
Think of it like 5 re-spins with locking symbols and you’ll understand how this bonus round works.
Landing a full strip of Bruce Buffer symbols on reels 1 and 6 triggers the special Buffer Bonus, you start this bonus round with just 3 re-spins of the reels, but every time a Buffer symbol lands on the reels this counter is reset back to 3 and will only finish after 3 spins with no new symbols landing in view.