I got this game free with PC Gamer magazine a few weeks ago, and I have to say I'm thoroughly enjoying it. I love strategy games so I sort of already knew what sort of game it was going to be from another Paradox game, Crusader Kings. I built my epic Scottish Empire by conquering most of Africa, Oceania and North America, whilst being fought by Spain and France, so it really does pose a good challenge. It is not the most welcoming game for newcomers, but having a look at the tutorials can help.
And, in terms of AI going off the rails, my game has the grand empire of Oman ruling over most of the Middle East and India, as well as the Kazakh empire ruling over most of Northern Asia. And also a strange case in the Byzantine empire fighting back against the Ottomans and defeating them. And yeah, I'd love to try multiplayer some time if I ever have any spare time.