Stack'em is an old slot by Hacksaw, it is available in many casinos as long as there is Hacksaw in the providers list. This is a high volatility slot, it may give you so many dead spins, many free spins but with bad results but it may give you nice multiplier. I'd say it is the nature of Hacksaw games and other high to extreme volatility slots. He did it even bigger multiplier on the same game but in other casino a day after he hit the one he shared here.