I searched, but didn't find help on this. I'm at the point in the game with a very large door that has a shield on it. I was given a laser beam and I don't know what to do with it. How do you destroy the 6 power stations to take down the door's shield? There's just constant waves of enemies that come, kinda like a tower defense level. Once I kill a wave, I get a few seconds (timer starts) before another wave comes. Hopefully someone will understand what part of the game I'm referring to. Thanks in advance. Just need to know what to do to advance in the game.