Game field is full of butterflies of different colors. If there are three butterflies of one color - you can turn them around with the mouse. Just click with the left mouse button between these butterflies. They will change their places in the given by you direction and, if three or more of them are of the same color (diagonally or vertically), they disappear. But the new ones will fly in. To move them counterclockwise, press Shift at first. To use a sort of prompting, click Hint button.