VGFacts

The game was almost made for the failed Nintendo 64 Disk Drive add-on. The game would've allowed players to import their cities from the original SimCity (also on the 64DD), and fly around it. It was shown off at Tokyo Game Show, according to UnSeen64. Unfortunately, the add-on was never released outside Japan, and sold poorly in said country, resulting the game being cancelled entirely.

Here are the links:

https://www.unseen64.net/2010/06/23/simc...cancelled/

http://www.ign.com/articles/1998/01/30/64dd-the-games