It's nice, but there's basically 2 problems with it.
1) due to a bug, there's no Plain Stone. I thought for a while this was intentional. I got the pyramid to 70%, but then my luck (and therefore my evil plan) ran out. I turned to the mission editor and found it was indeed just a bug (the trade routes aren't numbered properly. This makes them show up on the map, but they have 0 commodities).
2) 600 years is days of playing time, even though (spoiler alert) nothing much happens after the first x years.
I uploaded a new/fixed version that has the trade routes functioning properly and 100 survival years. Search for "Cross"
For a first attempt: Not perfect, but not bad at all!