Playability: I was really happy to play a map, where I have to begin at zero. Normally Im given a castle with thousands of archers and all I can do is to watch them killin tha enemy. But this time it was different. Even though, you should add some more invasions, because I had enough time to build up a strong unbeatable army. I think it would be good to disable some buildings in this scenario: especially market place.
Balance: This was the best element of your game. Maybe it depends on where you decide to build your castle, but I think balance is great.
Creativity: It is a classic stronghold map with only a few events in the game (I think some travelling fairs). You should add some more events, especially, when the time between separate invasions is so long.
Map Design: Only 3 here, sorry. I really know that is hard to make a good looking map, when it is so large, but if you try to add some rocks, hills, improve the vegetation and river objects (fords as well), it should be 4 or 5 next time. I see, you know how to use EQUALIZE TOOL, but you only did this on the highest points. If you try to use it mounds, it would be much better.
Story/Instructions: Well, there was no story, just a simple command, but I think it would be rather tiresome. Thats why 2.
I liked this scenario and I believe, that next time you will do even better work.