Doomsday Game: Build an Infinitely Upgraded Shelter

Countless people have suddenly traveled to a post-apocalyptic survival game, where they face the daunting challenge of surviving under the threat of countless natural disasters such as tsunamis, earthquakes, cold waves, volcanoes, and acid rain. In order to extend their lives, they must keep building upgraded shelters. While the situation is critical, the main character, Chris, discovers that he has a unique system that can be upgraded indefinitely! This discovery brings him unprecedented hope and opportunity.