Maybe going solo carol-singing wasn't such a good idea...

I think the building system is going to work like this: you can build or destroy anything within range of your king (that's him on the horse). Other units have limited demolition capabilities. For example all units can destroy wooden structures with fire, but only kings, catapults or cannon can destroy stone structures. Though the king is very powerful in this respect, he's also very vulnerable to attack, and if your king dies - that's it, game over. All your units are removed from the game and you have to start from scratch! This means that you can wipe out an entire army if you can get to their king and kill him. It also means you have to keep your own king very well defended. Because the game runs in real time you'll have to make sure he has a good bodyguard around him before you log off!