To Protect the Earth from alien invasion, you're given a ship class AT-021. But unfortunately the Earth doesn't have enough resources to supply new arms to the ship. Improve the ship by collecting weapons through battles and buy turrets to defend.
The great kingdom is in a state of war facing adversity as evil force from the Dark Fortress is creeping onto its territory. Cleanse this land of nightmarish creatures of darkness and the undead hidden behind the impregnable walls of the Dark Fortress!