Switch adjacent atoms to form lines of atoms of the same color. You gain points for positioning at least 3 atoms in a row or a column. You get bonus points if there are more atoms in the line. You will only get points for horizontal and vertical lines. To select an atom click on it, click on it again to deselect. After one atom is selected click on an adjacent atom to make them switch places. The game is over when there are no more possible combinations.