Take control of the Specialised Mech Advanced Remote Turret (S.M.A.R.T.) to protect humanity's last chance of survival against the Endless Hordes of bloodthirsty mutants! Collect resources and level up your mech with upgrades improving your chances of survival while unlocking special weapons for mass destruction. Exterminating the mutants also earns you resources to strengthen your position by placing and upgrading helpful defenses. You have just one chance to save what is left of humanity by gunning down the infected across three separate environments before they destroy your base or you!

Exploration of other worlds led to the infection of an alien mutagen which quickly spread across the Earth. The citizens of Earth's orbital city, Nexus, were the only humans left uninfected by what is now known as the Inmortui virus. To sustain the Nexus, the crew must make use of three connected teleportation pads that were installed at key locations across Earth before the collapse, however it is far too dangerous for a human to make the journey...