Nuclear 9's is a Power Spins slot game at the Microgaming casinos. Power Spins is a feature which can be activated on extra bet through button POWER. It can be played at 3x current line bet on max lines only. Slot game has 9 line. It means that you can place the bets from 12 (1 coin for each of 9 line) up to 120 (10 coins for each of 9 line).
When you make active POWER, a Rolling Reels feature will be available. Click button POWER SPIN to spin 5 reels. After spin and your win are paid, the winning symbols is collapsing. And you will see as the symbols above fill the empty spaces. If you have a winning combination after the symbols shift, your win will be doubled!
Collapsing of symbols in winning combinations will continues until you do not have a winning combination.