There's a pattern to level 6.. try and line up the big balls in a line, then go crazy getting close and clicking to reduce the bigger balls to small balls, then ignore trying to go around some of the balls, it's best sometimes to ram right threw them, get on the side that you can get the most shots off of, and fire rapidly, while picking the ball up
 "Four Second Frenzy"){kind=icon}
 "Monster Arena"){kind=icon}
 "GlueFO 2.0"){kind=icon}
 "Epic War 5"){kind=icon}