Okay, guys, I haven't read everyone's post because I'm short on time, but would you believe I tested that game? I've had this conversation in a another thread but...
Here's the skinny. I was picked by Nintendo to come play unreleased games at something they called the Evaluation Center. They sent an invitation to Nintendo Power subscribers located in the Seattle area, hence I got invited.
We would play the games and rate them. SimCity for the NES was the only game I played that never got released.
At that time, the SNES had been out for a little less than a year, and I had had plenty of time to play the SNES version of SimCity and compare. This NES version stayed unreleased for a reason. It was inherently flawed. The "block sizes" of the commercial, industrial, and residential zones were only 2X2, instead of 3X3 like they were in every other version of the game. Meanwhile every other zone was the same size as the SNES version, including gifts. This meant that you couldn't make donut blocks, and the city planning was all screwed up as such.
On top of that it was really slow. Too slow. The NES probably had some trouble doing all the math necessary to keep that game running at a decent pace, and it couldn't keep up with the changes as you made them.
It looked good. It had good music. Dr. Wright was there, but I didn't see any monsters. It's entirely possible that the NES version didn't even have monsters because a few other things were also missing.
All in all, it looked like a neat package, but since the SNES version was already on the market (and was a far superior game in every respect) everybody playing it that day slammed it when it came time to rate it. That might be the reason it never got released, because we made it look like nobody in their right mind would buy it if they'd compared it to the SNES version.