This is a single-player 3D shooter action game set in a world thrown into prosperity and chaos by the discovery of a new substance called the Eden Factor. You take on the role of Isaac, the commander of the UN special agency "Theseus," and use a variety of guns to thwart the conspiracy of the Lighthouse corporate alliance. You'll face off against not only Viruses, monsters transformed by mutant versions of the Eden Factor, but also Lighthouse's secret sterilization squad. Will you be able to witness the truth of this world?