

Two years have now passed since alien invaders attacked Earth and occupied our planet. Despite the aliens' overwhelming power, the human resistance is still active and is trying to locate a secret weapon called "Rainfall" before the enemy does! This weapon appears to be the deciding factor in the war for both sides. While a small, battle-hardened unit fights its way through enemy territory, the aliens are mobilizing their forces for a final blow that will wipe humanity off the face of the earth once and for all...