The biggest progressive slot available at Microgaming-powered casinos is Mega Moolah. The top jackpot starts at $1,000,000, and three other smaller progressives are also available. The progressive is the central feature of this game, and because of that, it has an exceptionally large level of volatility. You can win the progressive with any bet size, an atypical feature, but your chances of winning are scaled in proportion to the size of your total wager for the sake of fairness.
Mega Moolah slot uses five reels with 25 paylines. Coins range from $0.01 to $0.05 apiece with the ability to bet up to five coins on each of the paylines. Bet sizes start at $0.25 with all paylines activated. When you trigger the progressive bonus round, you'll be taken to a wheel feature where you get a chance to win each of the progressives. The smaller ones are hit the most often, and the largest is hit the least often. The three smaller jackpots start at $10, $100 and $10,000 for the mini, minor and major, respectively.
Another 15,000x regular jackpot is available for lining up five of the wild symbol which gives you another impressive prize to win. What's more is that you can pick up 12,500x for five of the scatters. As you can see, this Microgaming game is all about the big payouts, and that's why it has such a huge volatility.
In another atypical move, this game also has a nice free spins bonus round. Get three or more of the scatter for 15 free spins with a 3x multiplier. This only adds to the volatility of the game while giving you opportunities for massive wins.