Once you get to level 8, the Sweet Riches machine will unlock. If three candy box Scatter pieces show up, you're into the bonus game for this machine. These are chocolate sampler boxes, and like those samplers, you have no idea what's inside. (Why do they do that?)
You need to pick candy pieces, and hope you don't get the bad ones. If you get a total of 3 bad (green) pieces in the first four boxes, the game ends. You need to pass those four boxes to get this achievement.
The first box has 9 pieces. You have three different flavors, and match 2 of any flavor (ie, get 2 blues) to pass the box. (The flavors give varying amounts of coins.) There are one or no bad pieces in the first box.
The second box is the same as the first, but there are one or two bad piece.
The third box has 15 pieces, and there are 3 bad pieces.
The fourth box has 20 pieces. There are four bad pieces, and four different kinds of flavors you can match.
Once you pass the fourth, you have a bonus box, and the achievement pops. This last box has no bad pieces, so it's just a matter of luck as to how much of a bonus you'll get.