Cool concept, very confortable to play and the quest thing has a lot of potential. I'm sure you already have a lot of improvements in mind.
Just a question: At some point i had the goblin issue absolutely under control, and i only had to deliver quest and earn money. It doesn't look that was getting harder or something. But i read in the comments that there is an end game. Did i miss something?
After you've built all the available buildings, you officially "win the game" which is indicated by a pop up. After that you unlock two bonus buildings if you want to continue expanding your town, but they're visual only and the gameplay no longer changes at that point. And yes, many ideas came up, like other monsters that need a different bounty, or need groups of people (ensuring you lure the right classes to your town) etc. :)
