I downloaded the demo and played it on easy until the unstoppable demon hordes showed up.
It was a very enjoyable experience which brought to mind the good old days of BBS door games.
I have a few suggestions. First, it was unfortunate that there was no default for the Enter key, so I always had to type in a number, usually '0', which added a lot of unnecessary key strokes to my experience. This also caused army battles to be overly complicated. Battle would be streamlined if it were possible to default-none or default-yes the Enter key for various army types. It is also not possible to fire or sell the unique soldier types you can hire from Independent nations, which made my battles unnecessarily complex until the demons killed them all.
I also suggest the demo end in some way when nothing is left but the Demon hordes. The post-demon horde game is kind of empty, so the dev might as well just end it purposefully. Give information about why we should buy the complete game. It was not obvious to me what was missing, though there were some parts of the explorer pages that were marked "???" and others "not coded yet". Are these included in the final version?
Congratulations on your project.