Hello,
Great game, very fun. I just wanted to throw in a suggestion that while simple to implement will add a huge dimension to the game by stimulating a player’s mental ‘reward system’: the addition of very rich and velvety gold coins sound effect clanging together after the completion of a contract job. A thick, rewarding sound and some short piece of epic music to go with it (think the Ending music to Age of Empires 2). Do this right, take the time to make it epic and mid/end game will pretty much take care of itself because what players brains really get addicted to is the instant gratification.