Awesome! And great score.
I definitely want to add deck building, new types of cards (ability cards, Gods' miracles, etc), board-expanding mechanics and more.
Let me know if you have any thoughts on how to improve the game!
I'm glad you asked, I have several Ideas.
1. Make buildings that can affect other buildings, so that everything isn't just production, an example of this would be roads, you could make them increase the gold gather rate or amount of gold per each tile touching it (you already have the is touching feature for the fire), you could make other version of this I"m sure, but the road makes the most sense, also you could make dirt and paved road, making a upgraded version of it.
2. Make it less rng, add a way to make multipole strategys work, the way I recommenced to do this, is introduce a tech tree, and a market. You don't have to remove rng, but it would be nice to have less, this brings me to the next idea.
3. make it bigger, the map size, possible scaling aswell, I think a good niche to hit, would be a fast paced city builder. Right now, it doesn't matter much where you place things, I think you should change this, make it so that you have to place things in a somewhat ordly fashion or get better results, for example, you could make a wonder building of each type, and have it boast production of that type I think you should have a tech tree that unlocks buildings and, I don't have a better word for it, but methods, like, switching how the eco works for that playthrough, or enabling certan paths. (sorry for bad explanation here). Another idea to make different stratagys work, is add off to the side buildings, optional ones, that work for certain builds, but arn't useful for others. So that there isn't always one playthrough, sometimes you go for more wood, or overdose on stone for a reason, or gold maybe.
4. Another idea, add water buildings.
5. Another idea, and a placeablity system, so that you can only place buildings within a distance of other buildings, or maybe just only tiles you've explored (if you had a fog of war mecanic, but you might have issues with the fireballs for that) - The reason to add this would be for a statagy factor, now you have to think where you place things, if you combine this with my other ideas of buildings buffing others, or producing less if surrounded by certain ones (think the factory buildings in the og sim city, if you put house in near factorys, there value goes down), If you combine this, and add more tiles, it could be much faster paced and even competitive.
6. Longer, add a way to go long play, or just make the timer longer, the idea would be, that you can beat the game, possibly through making a really expensive wonder, and filling all of the tiles (plus upgrading them and optimizing it) would be very satisfying.
7. More uses for money.
8. Pop becomes useless after 4ish houses.
9. I don't know so much about the fireballs, clicking on them is somewhat annoying, I think it would be nicer if you have a lava system, that way you have to divert it from the town with walls maybe (could keep fireballs as an event maybe, but its not important enough as is.
10. More stone buildings, we only have one right now.
11. rework card system, possible keep rng, but make the cards more avaliable, just, more cards, I ran out of things to build so often, I would just be taking whatever I can get, make cards an almost constant thing to get, with lower level buildings easy to ger, people shouldn't be idle for too long, currently, they have to stay there, but are inactive around 70% of the time due to waiting.
12. Things work diffrently at night? mabye?
13. Title screen.
14. Saves.
15. Game modes.
16. High scores or otherwise a way to compete with others..
I had some more ideas, but I'm forgetting them now, I recomend you look at the game freeciv, it has some of the same aspects as your game, and I think you could get many ideas of things to add if you take and modify some of their features.