Doomsday Tower Defense: Awakening an Infinitely Growing Tower from the Start

One day, the sky split open around the world.

A blood-red countdown appeared above every city.

[The Global Tower Defense Era Begins]

[Everyone is bound to a personal defense tower]

[At midnight every night, zombie hordes spawn]

[Those whose defense zones fall will be erased]

[Survive seven consecutive nights to unlock a joint regional defense line]

From then on, human society was forced to change.