In the future, aliens invade the Earth in an attempt to harvest its carbon resources. Only the remains of Earth's military are left to save humanity. The player takes control of Lieutenant Riley Vaughan, a cybernetically enhanced human soldier and member of the underground resistance, whose mission is to thwart the aliens' plans and save the planet.
C-12: Final Resistance is a 3D third-person shooter somewhat similar to Duke Nukem console installments. The protagonist explores ruined cities, killing aliens and their cyborg assistants, while completing tasks such as restoring power to the subway system to progress further into the game. A sniping ability allows the protagonist to attack enemies from a distance, zooming in for a precise shot.