A good little strategy here, is to hit the spiders while they are just appearing on the screen. The reason this is recommended is because it's very dangerous, many players think that the closer the spiders are to you, the better. Wrong. Very wrong. The closer the spiders get, the more risk you take. This strategy works fairly well on the green spiders, as they are completly confusing, so use this tip and shut them out quickly! Do all in your power to stop them from reaching higher on the screen.