There's turmoil at the reef, with different sea animals forming swarms again and again. Each turn in Aqualin, the active player selects one of six stones and places it on an empty field. One player is trying to make groups of the same color, while the other is forming groups of identical sea creatures, with players having the ability to move a stone before placing a new one to form new swarms. The larger the group, the more points it's worth, and whoever scores the most points wins!