The playability was a four because, it was fun and also had a bit of difficulty. I personally don't like these kinds of games, but yours was ok. This is kinda like a less advanced tower defense game.
The evil armies attacked too soon. You could just barely get to the second age before you got attacked. I would suggest that you make the player start in age 2. The waves got really annoying from the south, the jarls in the last five minutes came every 20 seconds and you can only just hold them off.
I have seen plenty of these games before, they all have the same basic plot. Yours did not really stand out that much compared to the others. Try making an opening cinematic to tell you more about the story. That would increase this mark by at least 1.
Map Design: 4
The map design, was like the creativity. It was pretty much the same as every ones, three entrances to the town, passage ways through the forest. But other then that it was simple but effective, nice work.:)
You did not really explain the story as well as you should have, that made it similar to the other wonder defense type games. As I said an opening cinematic would help understand the story., a lot. That could make this mark a 5.
Nice job Alyssea, I hope you have more work coming *coughCough* Australia prehistory*cough*