Humankind is under attack by an alien lifeform that is secretly trying to undermine US democracy, bring down its government and harvest the DNA of its citizens. And that alien… is you.

In 1959, Cryptosporidium-137 arrived on Earth searching for his predecessor clone, Cryptosporidium-136. Crypto-136 disappeared after Orthopox-13 sent him to Earth to prepare for the large-scale extraction of human DNA.

Pox sends Crypto on a mission to harvest human brain stems (which contain alien DNA due to an encounter between Furon warriors and humans in ancient times) to prevent the Furons from going extinct. Furon genitalia have withered away generations ago due to prolonged exposure to their nuclear weaponry.

To accomplish his mission, he must battle US forces, infiltrate and sabotage secret government facilities and defeat Majestic, a shadowy government organization led by a black-clad figure named Silhouette.

The invasion is on!