How do you beat in brainiac justice league heroes

There is a bug in the programming. During the 1st battle with Brainiac you will be able to destroy only 3 of the 4 electric towers and for the 4th there will be a perpetual loop.
The solution: Exit the game and restart from the last save point, this time all 4 electric towers' protective covers will be down one at a time. After these are destroyed it is a cake walk killing Brainiac twice. However there is a twist in the tale, kill Brainiac and discover the story for yourself.