Doomsday Titans: The Invincible Fortress

When the apocalypse strikes, Bill Trudy activates the "Doomsday Bunker System." With just a welding torch and a modified harvester, he builds a mechanical farm on Sunset City. While humanity battles zombies and famine, he enjoys hotpot in a bulletproof greenhouse, plants toxin-resistant wheat and upgrades his farm into a steel fortress with heavy firepower and Titan Mechs.