Global Wasteland: Can I Upgrade My Shelter?

Sunspot outbreaks bring amazing changes, ice age prehistoric viruses, legendary zombies and famine! In such a doomsday, with only a shelter dug by oneself and a survival system picked up, how should one survive the crisis of the doomsday? In this unprecedented disaster, did you commit suicide out of despair and fear? Or are you struggling to survive and looking forward to a new future? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.