Doomsday disaster: Start by building a shelter

High temperature + glacial doomsday + earth disintegration + shelter upgrade
Extreme climate disasters occur alternately, surface creatures become extinct, and human civilization is heading for doomsday.
Su Wu travels to this parallel world and immediately faces the threat of doomsday.
Fortunately, he has obtained the doomsday survival system. As long as he survives, he can infinitely climb the technology and turn fantasy into reality.
Gardens, rice fields, forests and elf-like girls in the shelter.
Exoskeleton armor, power armor, mobile base, air-space integrated unmanned mechanical formation-
Build an underground shelter from scratch, and then upgrade it step by step to a giant fortress that can sail the star sea.
Finally, rebuild the human empire in that vast star sea.