You have *checks sundial* around 12 hours left to take advantage of Crusader Kings 2's Steamy free weekend, which would really only allow you to scratch the surface of Paradox's enormous grand strategy game, and that's assuming you don't take time out to eat or sleep or feed your pet ferret Bartholomew. So if you're interested in the game, like, get on it, but also stick around to hear about the next expansion. It's called Charlemagne, and it adds "new story events, the ability to create new kingdoms, and an additional century to play". There's also a new 'Chronicle' thingy that will keep track of all your incesty and warry medieval wheelings and dealings.
Paradox's update post on Steam opens with this lovely quote from the medieval scholar Einhard, four-time winner of the coveted Best Germanic Medieval Name competition. "Charlemagne stubbornly did what he wanted and refused to listen to doctors, indeed he detested them, because they wanted to persuade him to stop eating roast meat, as was his wont, and to be content with boiled meat." He loved a good roast, did Charlemagne.
Because it is the space year 2014 and nothing is ever simple anymore, Paradox are releasing four mini DLCs to complement this main DLC. "Period appropriate clothing and portrait packs for the Early Middle Ages will be released for both Eastern and Western Europe and the Dynasty Shields: Charlemagne collection will give appropriate coats of arms. An e-book of the medieval epic 'Song of Roland', will also be released on October 14." So nothing essential then.
That's the same date Charlemagne itself will be attempting to conquer your free time. While you shore up your defences, here's a development video: