Earth's Self-Saving Guide: Please Do Not Feed Alien Spectators

When the global zombie crisis broke out, what humans didn't know was that this was the 4396th reality show planned by the "Observer", an advanced alien civilization. They have set up a holographic live broadcast network on the periphery of the earth, and broadcast human survival at the end of the world as entertainment content to the entire universe for a fee. Each survivor's health, funnyness, and plot twists will be converted into interstellar rewards in real time.