Click on a bottle to choose it, then tap on another bottle to transfer the colored water. Make sure that the color you are transferring corresponds to the top color of the destination bottle or that the destination bottle is empty. Only the top color of a bottle can be moved. Plan your moves carefully to prevent getting stuck. Finish each level by filling all bottles with a single color. Move forward through multiple levels with growing difficulty. Employ the undo button to take back your last move if you make a mistake.