You are defending the colony from Alien Attack. You must defeat 16 waves of 6 aliens to save the colony . The aliens will try to knock out your laser cannon and you laser cannon energy batteries. Your laser cannon can withstand 2 hits. Your laser cannon power supply will only last for a count of 60 , so each wave must be defeated within that time so that the power supply can recharge, or else your laser cannon will be useless. You have a shield which can be activated by pulling down on stick. The shield will last for 1 second, but cannot be activated again for 4 seconds. The shield also puts a higher drain on your power.