Use the following strategy under the hard difficulty setting. In the first part, the organization of the machines allows you to win easier if it is done fast. Quickly hit the machine in the middle, then hit the machine in the right corner, followed by the one in the left corner -- always one leg and one head, so that it starts again. Do this three times and on the fourth quickly select which machine you want to fight and hit it. In the second part, run towards to avoid the machine's attack. Stay in the middle to prevent being attacked by homing missiles and getting stomped. If you get in position and can hit it, attack fast but concentrate on the head. The position makes it more difficulty but you have two chances. When the machine near attacks quickly escape from it. If you stay exactly in the front the others, the machines will hardly attack. During the beam attack, quickly avoid it and use the Stinger. To detect the beam, note that the near machine will face your horizontal line and nod before attacking. At that moment, avoid. After the near machine is defeated the two others will usually prepare to approach you. Try to guess your next opponent and take his life down and hit the other consecutively. Note: If you get far from the machines and go back, the near machine will usually launch horizontal homing missiles. Watch what the near machine is doing or wait for its attack to become safe to quickly avoid it. Do not run forward until you are safe or the machine will get you.