I'd like to see a way to drag across squares to build a lot of units at once. Speed up should definitely be faster and toggle, not hold. Also, counters for the achievements. Finally, please fix all those bugs.
The final boss is very easy with ranger, just fire a frost arrow and then keep shooping normal ones, after while you'll have to shoot another frost one and so on. Just make sure you fire your first arrow from above or below of the boss, so as not to alert the other monsters
 "Master of Fortresses"){kind=icon}
 "Hands of War"){kind=icon}