It's definitely a game you'll either love or hate, not really an option to be in between. It has absolutely no set quest line or storyline, you just drop into the game alone, and then it's up to you what you want to do.
My brother likes to build his army quickly and then lay waste to the countryside.
I like to build my army slowly, make lots of money, and fortify a single area.
It's completely up to you.
The mutliplayer is pretty silly though. We only use it when we're extremely bored and my brother and I go head to head to see who can get more kills. (Which is always me, cause I'm sneaky like that.

) I'd also suggest doing the trial version and seeing if you like it before buying. The trial totally hooked my brother. (much to my sister-in-law's joy...)