|Planetary Defense. Invading fleets must fight and destroy the Cannon before they can capture the planet. You can upgrade the Planet Cannon in several ways and add a Planet Shield to make it harder to defeat.|
Double RateCauses the planet standard cannon fires twice as often.
ShockwaveAdds a Shockwave Bomb launcher.
NuclearAdds a Nuclear Missile launcher.
FleetCreates an orbital fleet around the planet.
Auto-DestructBuildings and facilities are destroyed if the planet is taken over.