Sim City to the max -- 6 million residents

My wife gave me Sim City back in 1990, shortly after it was released.  I've created some interesting cities since then, but never anything like the "Magnasanti" shown in this video.

For anyone familiar with the game, this is a jaw-dropping creation achieved by tesselating a smaller pattern.  It's entirely subway-dependent, so no land is used for transportation (impractical in real life, but permitted by the AI of the game engine).  Zero pollution.  Zero crime.

There's a lot here I don't understand, but I am certainly impressed.

Via Reddit, where the video is discussed.