As already pointed out by others, there are no win criteria or events. The player does not know what to do in order to win, or what the parameters are for losing. As a freebuild it serves a purpose, but not for an economic scenario.
The relative difficulty of this scenario is impossible to judge, given the comments made above. May I suggest to the author that the map is resubmitted once the necessary changes have put in place to allow others to play a map with clear goals and requirements?
With the title 'Fort Knox', I was expecting something along the lines of a substantial fortified settlement to be either built or to defend. Rudimentary castle walls and towers placed on top of raised terrain doesn't leave us much to go for.
Map Design: 1
The landscape is rather crude, the castle area must serve some sort of purpose, but exactly what is unknown. The landscape has the minimum amount of effort put into it, but still doesn't deserve a higher score than this.
No story or instructions included within the zip file, nothing to introduce the map on the screen prior to game launch and a cryptic message on the downloads page here is not sufficient.
If the map is a genuine effort on the part of the author, but has submitted an incorrect version, then I will happily re-review this scenario at that time. If not, then I have no alternative but to recommend to potential downloaders that the scenario is best avoided.