I went from "Whoa, this is astounding for WebGL" in the first scene to "Ok, this probably isn't actually rendering on the client" as I saw some of the diffuse reflection shaders in the escape to "I feel kind of silly now" once all the other robots appeared.

The YouTube chrome is hidden, but the video must be in 4K; it looked like native resolution on my Retina MacBook Pro.

It's up to 1440p, played 1080p by default on my rMBP but I may have set that as the default a long time ago so perhaps you saw 1440p.

https://www.youtube.com/watch?v=44M7JsKqwow

Exactly. I feel a bit cheated.