Gemix — Crystal Charge Clusters
A 7×7 cluster slot with a gem theme. Filling the "Crystal Charge" meter with wins triggers several kinds of board-transforming features.
As you progress, the background world changes, and so do the features that trigger. Released before Reactoonz, it feels like the prototype of this line.
The presentation is a bit dated, but it's a good way to get a feel for cluster slot fundamentals. See the in-game info panel for detailed figures.