magical apocalypse and end of the world shelter construction kit M.A.

the world entered an apocalypse and 100,000 people are dragged into a 'game' where they will have to build a shelter capable of withstanding all kinds of natural disasters and radioactive monsters while they themselves increase their strength.

[the conditions to be returned to their world are to survive for two years while increasing their strength and reinforcing their shelter or die on the way].