Search for “SimCity 4” on YouTube, and you’ll see players constructing multilevel highway interchanges and intricate railroad networks, or maybe even a swooping flyby of a sprawling metropolis. None of these features came with the original game, which was released just after the turn of the millennium. They’ve been developed slowly and painstakingly over the 22 years since its release by dedicated aficionados — a thriving community that continues to push the game’s limits.
The…