When they land and are gold, they stick around for three more spins, unless you get another gold symbol, which resets the counter, the animal resets your counter, or you get enough symbols to trigger the Hold and Spin (in which all gold symbols unlock after that feature). The wrinkle is some of these symbols are gold. Like most games that use this model, six Cash on Reels and/or Wheel symbols will get you the bonus. They are awarded through a wheel feature, also available through the Hold and Spin. The game is in 50 credit betting increments the progressives are the same across the bet levels in a denomination, so your chances of winning the prizes/progressives are higher with a bigger bet. The version I played had a Tiger and Phoenix set of themes there are others that work a bit differently, so this is focused on those themes.
But I did have multiple sessions on Ultra Rush Gold during my recent cruise, one of their games with their version of a Hold and Spin bonus. I rarely write about Incredible Technologies games – for whatever reason they all feel a bit same-y to me.