You control two unique cannons that can fire cleansing bullets! It is your duty to protect the sea from getting polluted by dirty acid rains that fall occasionally! All you have to do is to hit the polluted drops (dark ones) with your bullets to clean them before they reach the water?s surface. You will lose the game even if a single drop of polluted water falls into the sea. Also you have limited supply of cleansing ammo and you will also fail in the game if you lose 5 bullets.