Great game, but I think that more science related things should be added and the gold generating machine should have some kind of exponential money gaining amount.
So, lets say that there's a 50/50 chance of the machine to give money one day, in some way, like if the scientist, in some random days, ask you for more money, you could upgrade that and goes to 75% chance or 100%, after that, there could be upgrades to the amount of gold gained, lets suppose it is 60% ($20), 35% ($60) and 5% ($150), by investing you could increase like, 50% ($20), 42,5% ($60) and 7,5% ($150), or even more after that.
You could make Jester's $700 show cost less, last more and have a greater return on money.
I think the Sultan should have more "agreement' options too, or maybe you could ask your assistant (Royal Advisor) to make YOUR agreements with him, like sending or buying spices, merchants, etc.
I love your make and I with you could read this and agree with my ideas.
Thank you for your time.