Threediopolis is now in release 3, with many bug fixes, text tweaks, and new aids for the player. The walkthrough/logic was tuned up.
While the game is being uploaded to IFArchive, the dropbox link on the game page should work.
Empty commands now nudge you to an easy puzzle left, and some "close" sectors even give hints.
But wait! There's even more! You now have a new game of sorts. There are 80 pieces of scenery to find in Threediopolis. They're not intended to be easy, and you don't have to solve them all.
Thanks to Sean M. Shore for some really great testing work to make sure my new features were up to scratch and even pointing out a really good feature that sadly had to wait for release 4. I fixed a lot with his help, aesthetically and technically.
Source code is available if you want spoilers.
Also, to view the scenery sub-game directly, type
(Spoiler - click to show)SEE NEW SEENS.
Looking forward to other recent IFCompers' revised versions, too.