In a world overrun by zombies, survival is difficult, but I suddenly gained an all-purpose apocalyptic upgrade system.
What is this?!
By killing the zombie and completing tasks, you can earn upgrade points that can be used to upgrade anything. With this, I no longer fear material scarcity, I just have to keep upgrading. From fruit cores to trees that last for millennia, from wild fields to super farms, from broken guns to plasma explosive weapons, from peas to super zombie-killers, and from paper airplanes to F22s. With this system, a single person is equivalent to a whole city!