Recently, I was sitting in discussions with ben and ed and found such a headline "Unused level" and saw a level that I had never seen before. I immediately went to check and it turned out to be true to play this level, you need to write the following command in the console

open level03_verticalup

The level has no name (I don't know about you), this level is also impossible because in the end they probably forgot to add a gun and it's simply impossible only with the console (I didn't find this level, but Nicacolak here is his steam profile https://steamcommunity.com/profiles/76561199246451617

I repeat, it was not me who found it, but a man with the name Nicacolak from above link

I didn't pass the level either