The city generation is really awesome, incredible work there. I love watching the smaller green road lines populate, its very satisfying.
I spotted a strange bug I think with one area having two dots inside it, both named the same? Not sure if this is intentional, but it did let me build a path between them.
Im not sure im understanding the gameplay correctly though. Are you supposed to just try to maximize score? I couldn't quite figure out what I was supposed to do, other than plan the routes and use that to determine which were the cheapest ways to connect the most cities with largest population?
Regardless, its a game jam and I assume you didn't have time for some mechanics. The art style and procedural generation here is really a feat you should be proud of.