Global Wasteland: Unlimited Upgrades for Vaults

When the natural disaster comes, the whole people travel through the wasteland world and face the challenge of death and survival!
Terrifying acid rain, monstrous floods, burning cities, global glaciers, super radiation...
No one is spared!
If humans want to survive, they can only build shelters and accept the baptism of natural disasters one after another.
Fortunately, Soma has awakened the doomsday survival system!
His shelter can be upgraded infinitely!
【Wooden Door】→【Iron Door】→【Alloy Door】→.....
【Wooden Spear】→【椆 Wood Spear】→【Electromagnetic Spear】→.....
【diesel generator】→【biological generator】→【thermoelectric generator】→.....
When everyone was running around to prepare for the next disaster, Soma was already fully equipped and ran rampant in the wasteland world.
"We are still lighting oil lamps, and everyone's refrigerators are used!"
"His shelter is said to have walls tens of meters thick and is the safest place in the world"
"In my lifetime, I want to enter the Sushen Refuge and live for a day"