Brett Camper thinks it would look a bit like this.
In his own words, the 8-Bit City Project reworks “city maps in the style of 1980′s video games” and in the style of any good art, it takes two classically recognised things and, well, smashing them together.
The 8-Bit maps are inspired from all the games you played thirty years ago on ZX Spectrums and the Nintendo Entertainment System, where you had to do something heroic in an RPG, while the maps are from, err, the maps of the cities.
London is there, as well as Austin, Amsterdam, Paris, new York and San Francisco plus a few others. It’s worth a little exploration
More at 8 Bit City