How to win. Get in the middle of the 0 and drill a small hole with your own missiles up through the 0. From now on you will be safe and most of your shots initi

How to win. Get in the middle of the 0 and drill a small hole with your own missiles up through the 0. From now on you will be safe and most of your shots initially will hit an invader. Once you get down to the last one it is a matter of timing. If they break through the 0 and you are in danger, move under another safer part and drill a hole again.