Your city has been taken over by enemy infantry, and they're coming for you next! As part of the military, you have to take down the invaders while keeping yourself safe. To fly, move the mouse around. This will make your helicopter fly up, down, left, and right. You can also use your mouse to aim at enemies. Your red target will show you where you are aiming. Click to fire! You need to take the invaders down fast, because they will start shooting at you as soon as they see you. If they shoot at you too much, your helicopter falls out of the sky!