Back in the day (2002) modeling was very low poly. But damn, just reopening those old works of mine, I crashed Windows 10 :) "Your computer is running low on Memory". And believe me at this time we weren't working on i7 Quad Core with 32Gb of RAM :)
But I'm glad I took some time to clean the mess. It's fun to see old works like that.
Sadly those levels were looking "way better" thanks to vertex color information. We had to paint vertices by hand in order to create the atmosphere. But I couldn't figure out a way to get this back in Sketchfab, if there is a way ?