First off, I would like to say that it was a rather interesting first map. However, the score may seem a bit tough, but I have included plenty of things you should be adding and playing around with.
A first glance, it seemed a rather interesting map, but once the map started, the entire game quickly degenerated into a situation where my ranged troops were sniping everyone else off, and where my melee troops were playing hide-and-seek with the enemy, though they were extremely aggressive in attacking. There were a few rather serious flaws with how the map functioned, I'll get to that later. The mix of attackers (I think) was heavily influenced by BMC's mixtures, strong, but effective, though in this map, did not seem to fit the bill. I'll say this for playability: you need to playtest!
Balance was off, playing on hard, it was in reality far too easy. By simply bunching up all of my ranged troops in a single tower and placing all my melee troops in a choke zone, I was able to fight off all the attackers, without the help of any traps such as pitch, etc. I suggest that you change the map so that the player has to fight off every scripted attacker rather than simply setting up a repeating invasion and a counting trigger. Like with playability, this map needed more intensive playtesting.
I didn't really find anything new, but I did see some solid effort at making an interesting map. The concept wasn't too original, but I liked how you switched the lord for a swordsman. I doubt that it would have worked, though. Try for example, learn the lowered walls trick, and build a more interesting and complex castle.
Map Design: 3
Map design was still not a big surprise. Though it did show a bit of improvement. I seriously advise against writing words in the map - even if it looks cool, it seriously ruins the look of the map with adding something artificial.
The grasslands were... plain. Not much broke up the monotony of grass... grass... cliff... and yet more grass. Try mixing dirt terrain along with some stones and rocks, and sprinkle on a few shrubs. I guarantee that it will look far better.
The cliffs were rather plain cliffs, they could have been spiced up a bit by placing rocks, etc. to make them rougher.
Now for the big flaw... the bridge. Simply by deleting the stone bridge you have put in, I could render the map totally functionless. It looks rather good, but you need to be careful with them. Especially with the bridge, time spent on the lowered walls trick would be well spent. Remember that you need to try to make your map as cheat-proof as possible to avoid people taking advantage of the map.
Really, not much of a story. For a decent score, aim for about a page of 12pt size, single spaced story. It usually fetches a decent 4 to 5, and you can use it to explain some of the terrain too. Here is where you should use the brunt of your imagination. The lack of a story put me off playing the map at first.
You show a lot of promise! However, I would still consider this to be an unfinished map, mostly due to its serious problems with terrain and balance. Remember what you learn here: make the terrain more interesting, but most important of all, playtest!
I hope you have fun creating maps and please, try my maps. :D