I missed a couple days so I'll fill them in albeit a little brief.
Day 7:
This day I decided to tackle the title screen. I knew I wanted a ship to be forefront and after Googling around for a while to find a base image, I found an artists impression, for National Geographic, of the volcanic eruption of Thera (Santorini) and the Minoan evacuation. It was perfect and relevant! All I had to do now was take this image and make it into the 4 colors, THIS was no easy task. After playing around with direct conversion it was clear it wasn't going to work. I ended up cutting out the individual elements of the image (sea, sky, volcanic plume, ship, etc) and coloring them individually, all of it other than the ship was basically re-draw anyway:
I also spent time working on path-finding. It's not-quite A* but I plan to add that given time at the end, not for it's slight speed advantage, it's only a minor change, but to allow it to favour diagonal routes. As atm it prefers taking one big right-angle. The distance wouldn't change, just make routes more zig-zaggy and SEEM more direct.
Path finding allows roads now, between inland cities and port towns, the fog of war will clear all along the road when any part of the road is discovered. Path-finding allows the coast to be blocked except at ports, and allows deep water to be blocked.
Day 8:
This day I worked on the trading system, turning local resources and imports into exported resources. The higher tier resources produce more culture in the cities they are sent to. Gain enough culture in a city and you can start controlling it's trade like it's your own city. It is visible displayed as your city, but your cultural influence there will drop if you cease trading, and revert to the city's affinity culture.
Day 9:
And today I finally implemented the disasters. These are a key aspect to the game, they are the thing you have to survive against. There will be different kinds of disaster, but I think this'll be the most prominent as well as the most destructive. This is a volcano, this can erupt both inland and sea the sea, if near the sea however, it will trigger a tsunami which will spread through the sea, destroying port towns in it's wake.
Cities take damage. This will put them out of action for a while, preventing a quick re-population. Cities will not lose their cultural affinity (if of a culture other than Minoan), so even when they recover you will not be able to trade with them until the native population (culture) has recovered to a certain point.