Okay, I finished all the campaign and I love the game. Good mechanics, simple but just enough visuals, enough of a challenge even when it seems unfair at the beginning. Two small things about AI behaviour:
1. When blocked and left with no moves, AI still hires villagers even though it will only lower his income and stall him
2. AI uses castles only as a mean to protect its towns, which is also a bit of not the best move, it stalls him especially since he does so late in the game when there's plenty of knights around.
Anyway, the game is great. I'll be glad if there'll be more levels