It looks like some work has been put into this, so well done, especially since i myself have not. That said, I'd like to see it go further.
"The Archerland", as a title, is a little hard to pronounce because of the "er". It doesn't quite role off the tongue with ease like other titles might. Perhaps if you were to make a second it could be called "archland"?
Another problem lies in how the instruction book is layed out. I would argue that very few could handle reading that entire booklet for several reasons: The font size is too small to read comfortable on the sized game screen; There's to many words per page, with not enough indentations; and, having only text to rely on means its much harder for the gamer to know what your talking about, especially if they can just ignore it and get the tutorial at the beginning of the game to.
Now, for playing the game. I've always liked archers, and playing the game with an emphasis on using only archers sounds like fun to me. I think you can develop the game further by looking at what works well and what doesn't. Realistically only you can determine that, but i'd like to provide you with what works for me and what doesn't:
1) I like the options of improving the castles surrounding areas but not having to choose were they go. I think if your going to be waging battle against something, you don't have time to really make those decisions, although I would still consider it as an option.
2) There's obviously something wrong in being able to build a brick wall around the entire castle but not repair or improve the castle itself.
3) The enemy characters are just to consistent. I'd like to see these enemy soldiers look like they have a mind of there own by either changing there weaponry or learning from the "archerlanders" and develop bows of there own. Just to keep it interesting after the 3 month or so.
4) Storyline? I think it could benefit from one, but like many games is not necessary, which brings me to my last point.
5) Environment. Personally, those random zig zag lines that appear in so many other defend the castle games has never worked for me. I dunno, i just find it odd that the enemy soldiers won't walk off the beaten path because there afraid of grass or something. What i'd like to see is a reason as to why those soldiers are walking that path. Maybe change to a mountainous area or something.
In conclusion, its a nice game but there's definitely more places you can go with it. which is why I gave a 5/10. Its not to discourage you, but I think it sets the bar for improvement. Lastly, I like the game menu and its background. Anyway, thanks for reading, and good luck,