Swap two adjacent gems to line up 3 or more of a color. Matches burst, gems fall, and chain reactions stack a combo multiplier for huge scores.
4 in a row = Flame (blasts a line) 5 in a row = Prism (clears a color) T / L = Starburst
Tap a gem then a neighbor, or drag one into the next. Made no match? It swaps right back.