Portal 2 PeTI - "Cosmogony 3" by  DreëY and Aleš Pěnkava
Channel: LB
Date: 2016-03-09

https://steamcommunity.com/sharedfiles/filedetails/?id=257351847
Blind playthrough.

This video is also on Twitch: https://www.twitch.tv/lb___/v/112045659