Somewhere in an alternate universe, the NES Classic could include SimCity, which today would be a retro title that first launched on the original game system 27 years ago. Unfortunately, in this universe and this timeline that we occupy and where you’re reading this, SimCity never got released to the NES. However, a prototype did in fact exist,

Source: Hot Hardware – Unreleased SimCity NES Prototype Emerges And Is Finally Playable After Nearly Three Decades