There are three enemy races that the Helldivers have to work together to defeat: the Bugs, the Illuminate and the Cyborgs.
The bugs are a species that have evolved for millions of years and have always come out on top in the game of natural selection. They are sentient creatures that live and fight in groups between three and ten specimens per group.
How the bugs manage space travel is yet unclear, it may be that unhatched infants or very rapidly evolving, super resilient microbes are launched into space during planetary impacts such as meteoroids or even planetoids.
One thing is for certain, the bugs are everywhere and if they are not destroyed they can spell the end of mankind.
Highly sophisticated, their civilisation has endured for several hundred thousands of years. They call themselves the Squ'ith. Originally aquatic, the creatures dressed in ceremonial robes have managed to create a vast and extremely complex neural network for space travel.
The species have, since their first tentative steps towards the stars, produced weapons of mass destruction in large scale and as such, is something that the people of Super Earth cannot ignore.
Once human, these terrorists have broken away from the peaceful ways of Super Earth and are fixed on mass destruction, devastation and ruination.
Utilising inferior technology, they have become obsessed with the manipulation of their bodies and constantly seek to pervert the skin with machines that according to them, gives them a higher meaning in life.
Cyborg leaders have recently declared their sovereignty from Super Earth, stating violently that "Super Earth's ideals are a lie and the people are brainwashed" in an attempt to bring more followers to their heinous cause.