Destroy the attacking missiles with your own missiles by catching the attacking missiles in the blast radius of your own missiles. Use the Z, X and C keys to launch missiles which fly to the crosshairs (controlled by the mouse) and explode. If one of your subs is hit you loose all remaining missiles in that sub for the rest of the attack wave. Enemies get more numerous and faster as the game goes on. You get extra missiles for the rest of the game each time you destroy all enemies but you also have a limited number of missiles to defend with so use them wisely. Once all islands are destroyed the game is over.
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