To start with, the game is built on the Megaways engine, which gives a random number of symbols on each reel for each spin, creating a huge maximum number of paylines. There is also the Duel Reaction feature, so that when symbols cascade from a winning line, they drop from both directions.
Four GOLD symbols will start the free spins mode, starting at 12 plus five more for each scatter, and chances to win more during those spins. This mode features an unlimited multiplier which increases by one for every time the symbols cascade.