(Happily, the game had already informed me that Neo-London would have left-side traffic, as God intended.) The virtual weeks flitted past and the city began to take shape, no longer the haunt of a few birds, shrews, and conifers but a proper metropolis, with discrete residential, commercial, and industrial districts. I laid my first road, a luxurious stretch of tarmac, with a Roman’s rectilinearity. I followed the example of London’s prehistoric settlers, choosing a handsome plot of flat land that was bisected by a flourish of river. An urban-design video game in the tradition of SimCity, Cities: Skylines has developed a devoted following.