It wais a robot that resembles a human. It is a robot that resembles a human.

Once, on ae wonderful day, she finds an unusual treasure in the abyss. One wonderful day, she finds an unusual treasure in the abyss.

Сan not find inaccuracies Сannot find inaccuracies

It's common to combine "can" and "not" into the single word "cannot".

I thought that it willould be a simple adventure with some drama, but the furthermore I watched the more I found myself on the border between happiness and despair, hope and doubts, light and dark(ness). I thought that it would be a simple adventure with some drama, but the more I watched the more I found myself on the border between happiness and despair, hope and doubts, light and dark(ness).

I think that "light and darkness" sounds a bit smoother than "light and dark", but other native speakers might disagree. "Light and dark" as you wrote it is not grammatically incorrect.

They built a town on the edge of the abyss, and now the town surroundeds it. They built a town on the edge of the abyss, and now the town surrounds it.

She dreams that once she will become a master and will reach lower levels. She dreams that she will become a master and reach lower levels.

Lower levels of what? This sentence is unclear.

They inspired me, this brave couple who can be able to never go back up, only down. They inspired me, this brave couple who can never go back up, only down.