Be a Lord - build & defend your castle - crush your enemy!
Great start. I have some feedback you can do as you please with. ;)
An indicator of time passage would be nice. be it a clock hand, or a sun or shadows, etc.
It didn't appear attack value above the number of attacks did much, but only keep the defenders to losing 1:1. Once you get ahead, the challenge of the game drops off.
I enjoyed the 15~25 minutes I played.