The first feature option is the gold rush! feature. If you get this feature, you'll get 12 free spins, during which the bullion can appear anywhere on the reels, not just the 2nd and 4th turntables in the base game. Getting 3 or more additional PayDirt logos will trigger 12 free spins.
This game has become the favorite RTG online slot game for many punters, specifically for the cost and difference of free spin function opportunities. If you happen to like gold mining, it's just a icing on the cake. Another interesting game on the same platform is the Jumping Beans slot machine.