If the bonus isn’t that important, finding a standard Double Diamond or Triple Diamond machine would be a smarter play. This effectively makes that last credit like a feature bet – a good chunk of that money is going straight to offering you a bonus. Like Pinball, the last credit does two things: It increases the top payout, and it funds the bonus game.
It’s a single line game, so winning combinations need to show up in the center of the reels. It used Triple Diamond as its base game I’ve seen Double Diamond used as well, and it wouldn’t be surprising to learn other variations exist. This particular one is a three-credit version two-credit versions also exist. While in Las Vegas, I came across a typical example that you can find on casino floors. But like Pinball, it’s not a game at all, but effectively a bonus game add-on to many of their other popular titles.
Top Dollar is a game that has enduring popularity on the casino floor.