3 weeks ago, John Romero did a play through while discussing the entire design and build process of the game.

It was actually pretty cool how they designed the first room to demonstrate almost every new feature of the engine and how the first level is made to walk you though most of the new gameplay features.

https://youtu.be/PU7HkttPfAo?si=LnD4vJeCiUojhojt&t=728