post-comp repository for my Spring Thing 2016 game
The original release was in April 2016. The second (and likely final release with major features) was on August 14, 2016.
Fourdiopolis builds on Threediopolis's code base. It's meant to be a lot tougher than Threediopolis, and with more scenarios. The final one in particular may require logic leaps not seen in Threediopolis.
Zarf's python regression testing scripts were used extensively to weed out bugs. They may be useful for your own Inform projects.