Protect you city's. Destroy incoming asteroids, meteors and saucers whilst charging you defence and repair meters.

Select those meters to deploy shields and mines, or repair buildings and missile stations. Super charge those meters for enhanced capabilities.

Take advantage of the different types of asteroids with a direct hit to unleash there destructive powers on neighbouring asteroids, but be careful you don't wipeout the asteroids that charge you meters.

Good luck commander!