This is a lovely game. As soon as I understood the specific requests that the game makes, I started having a lot of fun. I'd like to suggest the addition of goals or achievement-like things for future versions of the game, like requesting the player to build a village without fields with a given number of houses, or asking to build a rail with X straight pieces directly connected, for example. It could be a hard mode, for example.
There's also something else I'd like to suggest for future versions: having the game export a satellite view of the map at the end, showing the player what he accomplished and being able to save that in JPEG or PNG, for example.
Anyway, I love this game. You guys did a great job!