I enjoyed this simple game. Here are some feedback:
I mainly struggled to figure out the right amount for a quest. Perhaps you can give have a small indicator that shows how many % of adventurers will be willing to take the quest at that price, or show one of 3 states: 'generous', 'fair' or 'stingy', before the player posts the quest.
If the map could give visual feedback on the quantity of adventurers and goblins, it could add to the immersion.
Overall, good job on the game!