Originally Posted by shieraz
Keep shooting at the center tower. That will be destroyed and you finish the mission. Just remember that time is running out. So finish it within clock.
You have to destroy all the enemies but it's quite difficult because if you get too close to the center, you'll get electrified. You can only go around (right or left).
You have to aim towards the enemies that are hiding behind the moving walls.
It's quite hard but it gets easier once you upgrade your missiles.
And if you get a shield power up, you're immune to the electricity and you can get in the center of the screen for a few seconds.
Hope that helps, I was clueless at first with this level, too.