You're running a dual-wield cannon setup that shoots purifying rounds. It's up to you to prevent the ocean from getting wrecked by those nasty toxic acid showers that pop up now and then. Your mission? Frag the dirty drops (the dark ones) with your ammo before they touch the water. Game over if even one dirty drop splashes into the sea. And watch your ammo count, because if you waste 5 shots, it's GG for you.