In year 2028, earth was attacked by the outer space invader “Aggressor”. The huge levitation object called the “Hivecraft“ which is indeed 1km in total length, came flying suddenly from the outer space, and began to attack all parts of the world by dropping numerous insect looking huge creatures and murder weapons. It flew over United States to Russia, Asia, the Middle East, and Europe only in three days. Human beings established a ground defense force (called the EDF) ahead of the national fence and fought back against the invaders. However, the war situation was in bad condition and the beautiful cities began to turn into mountain of rubbles. As a result, the important military bases of the world that could possibly be opposed to the invaders were all already destroyed. There were nothing left for the human beings to do and all they could do was to wait for the world to end….