I love games like this, and love the concept and context. Sound effects are nice and the highlighted tiles are a nice UI addition. The game, in its current state, is just too easy, I'm not sure if it's a bug or if the AI just needs further improvement but I played 5 times and basically just moved 2 warriors out of the way and then moved my king to the corner, the orcs didn't seem to care about killing the king?
You are right, the underlining system for orcs to calculate the best move is there, where it's suppose to add points to potential grid places to target king first, then vikings, etc.
In it's current form AI is pretty much just random moves, while it would be quite quick to implement these rules, unfortunately I got stuck with trying to publish it out of Game Maker in HTML version, so figured it was more important to get it working in browser over all the polish, purely from play-ability point of view.
Thanks again for your kind words, few of my mates have said I should keep working on it, and positive feedback like this definitely makes me want to keep going on this game :)