Earth Online: Prison No. 13

Humans are creatures who live atop the Tower to Heaven. They worship the sun and fear the ground.

They had grown accustomed to this life. They were born in the tower, grew up in the tower, and died in the tower.

They believed the tower could protect them.

Five hundred thousand years ago, they built the Tower to Heaven, thinking they had preserved the last spark of life.

No one knew that this post-apocalyptic world was merely an iteration of a System called [Earth Online].

Humans believed the gods were dead and that they were the last masters of this world.

But it seemed they had forgotten one thing.

If the gods really were dead...

Then who had built these eight towers?

And who had left the civilization-devouring corpses on the ground?

Why did the corpses call a sixteen-year-old boy:

[Kin.]