Humans are not alone in space, in 20XX an alien force attacks the Earth suddenly. The invader calls himself Azyma Empire. To destroy the Earth, Azyma’s army built a solid military, which bases on the Moon’s dark side. Besides, human intelligence discovered important information. After the first attack on Earth to test military power, Azyma built a system of destruction weapons on the Moon. With this weapon, the enemy could easily erase all life on Earth. Facing the extinction danger, Earth Defense Force’s Command – E.D.F requested a special mission. Humans would launch an attack on the Moon’s dark side to destroy the Azyma Empire’s base and weapons system. In which, you were one of the combat pilots who sent to perform this mission. Players would have to control XA-1 (a modern fighter with many powerful weapons systems) to fight the alien fleet.
In Earth Defense Force, you can use many different types of weapons to fight the enemy. The game has eight types, including Explode, Super Laser, Laser, Photon, Atomic, Vulcan, Homing, and Grenade. Each offers a unique strength to use on the battlefield. Before starting, you can choose the type of weapon to use. With horizontal screen movement, players are free to move in 4 different directions to fight. The combat missions arrange according to each specific level. At the end of each level, you will bring a boss to conquer (a spaceship of large size with many different weapons).
On the screen, the Azyma army spacecraft will appear continuously from different directions. Therefore, players have to pay close attention to avoid enemy attacks. Slow reflexes will cause you to surround by Azima’s fleet. Meanwhile, the enemy can destroy XA-1 quickly. Besides, your spacecraft offers three shields to protect. Every time a bullet hits, a shield will lose. The mission will stop after all three disappear. In particular, you can increase the number of shields through achieving certain points (own five or more shields).