This area can be entered once all six base battles have been cleared. The battle works in a similar way to the fights at the bases. At the beginning you will be facing four units of Stormtrooper Aces and two of Special Aces. As their name implies, the Aces are much tougher than their regular equivalents - watch out for the Special Aces in particular as their use of Explosives can come as an unpleasant surprise.