At the End of the World, I Have a Flying House with Infinite Upgrades

An unknown disaster is sweeping the world. The zombies are swarming and mutating, and conventional headshots cannot kill them completely. Reborn people mistakenly believe that reviving their lives can change their destiny. They took the risk and entered the doomsday shelter early, never expecting that this would trigger a more severe test of survival. When mutated zombies sweep the world, even a hundred-meter-high wall cannot hinder their progress. When people fell into despair, a flying fortress suspended in mid-air suddenly appeared, giving mankind the last hope of survival. ....... Xu Shuai accidentally obtained a flying house, which can be upgraded infinitely after activation. It can also develop potions to enhance physical fitness, new weapons, and special combat uniforms. So while upgrading the flying house, expanding the territory, raising the height, planting crops and raising animals on it, he also recruited capable people and sounded the clarion call for counterattack.