When starting a level, shoot the enemies when they appear and run for the corner. All the enemies will go towards the center, where you can pick them off before moving to another corner. always kill the agents first. If one goes off-screen, do not chase after it. Instead, wait until you can see them and do not get too close. To kill large groups, use the Hell Bird. If you have the stinger, strafe as you shoot to make the rockets fire in a line. Basic enemies cannot dodge this most of the time. If you have the ADG Launcher, try to be as accurate as possible with single enemies; the grenades move slow and you do not have too many of them. If you get surrounded, get a Giga Torch and run in circles, shooting.