Just what I was looking for - a game in which I make myself an impregnable fortress. There's something supremely satisfying about constructing a wooden and stone deathtrap which minces attacking enemies. It works fine on my little low-powered, low cost netbook and rarely requires the kind of twitch mousing the touchpad hates.
This game is bursting with personality and detail. You can enjoy watching your peasants going about their business with some surprisingly detailed 2D animations. The battles themselves are more about preparation than reflex, letting those of us who prefer to sit back and let our plans unfold enjoy ourselves. Taking a keep seems, to me at least, less fun. But hey, if all you want to do is build, then you can do that in the sandbox modes.