Form groups of at least five crystals to remove them from the board.
The larger the group is the more points you get. Select a crystal by clicking on it, then click on a free point on the board. The selected crystal will move to the destination, but only if the way is free.
Locked crystals cannot be moved and cracked crystals explode clearing the area around. Move the heart symbol next to a group of crystals to change its color.
Don't let the board get too crowded, or you will loose.