Clear each level by removing the atoms in the correct order. Can you predict the merging of the molecules so that there's none left at the end of each level? On certain levels there will be all different kinds of combos that will need to be done in order to pass the level. If you make a mistake use the undo or the restart button.
Use mouse to select combination of atoms. 1.The colour of the atom you click on does not matter. 2.Each combination must contain the same coloured atoms. 3.Only one atom can be left unpaired in each combination.