Thanks, glad you liked it! UI/UX is definitely an area we're still learning and looking to improve, I have looked at the UI Material Lab project before, but haven't got into the animations and fancy things yet.
For the Level 2 art, the volumetric fog does play a big part. I raised the height fog up to increase the density a lot, then the rest is just lighting between emissive materials in the building windows, and playing around with the colours of the sky like the Rayleigh Scattering colour and light colour.
- Alice