Might be misleading to call this a castle simulator. It's really more of a base-building RTS game--with lots of emphasis on building and protecting the base. Absolutely wonderful game in any case!
There's much more of a politico-economic aspect than in other RTS games I've played: various resources to manage, and you have to watch your subjects' morale too (while also taxing them to get the gold you need). It works because you're at a walled-in base (after you build the walls), not scouting and conducting seek-and-destroy missions against a hidden enemy. However, the game does include many features, so you can assault enemy castles as well if you like.
The excellent tutorial eases you into the game, and the combat campaign progresses--at first--in baby steps, giving you time to learn and try new things out. There's also an economic campaign, which is surprisingly interesting, though I haven't gotten far in it yet. Besides the two campaigns, there are stand-alone scenarios, which you can edit or customize as you like. There are also historical scenarios--various actual castles you can try defending or assaulting.
The audio-visual effects are great, in my opinion. One small downside is that there's nothing like a smooth-scrolling camera; camera angle shifts 90 degrees at a time. But actually you don't even need to use that, as you can just press the space bar to make everything above ground level disappear. That's a very handy feature; it allows you to do most everything from just one angle.
The game can be very challenging, if that's what you're looking for. Even on Introductory level, it has been too hard for me at times, and I've had to replay a few campaign missions. I got through them, though; and I've gone back to replay them on the Normal difficulty setting and won there too. Some of the early missions are child's play, but they get tough soon enough.
Throughout, there's a bit of humor mixed in. It's not obtrusive, but it's there, and you'll find yourself smiling at the remarks of your scribe, your advisers, and enemy leaders. Though this is a serious enough game, it doesn't take itself too seriously. For me, that helps take the edge off and adds to the enjoyment.
Top-notch game. Highly recommended.
