First let me congratulate you, the game played! I didn't find any errors that obstructed playing, so good job.
On the other hand, your scene design needs some work. Nightwolf has an excellent guide on this, and you can find it here at Zeus Heaven.
The only other thing I noticed was that you had to wait quite a while to fulfill some of the goals.
For instance, having the monster come early gives the player more control over how long the episode lasts. Conquering the city in the first year, then having to wait several years for the monster to come can be a bit tedious.
You did a great job for a first adventure! I would rate it very easy for beginners.