Is this a game you can more or less pick up and play?

I'm assuming there is a tutorial; is it comprehensive? How long does it take to complete (the tutorial)?

The civ series just threw you in the fray if I remember right with no tutorial or anything and it was a hard game to learn (well, at least would have taken too long to get the hang of it for my taste)

To be more complete in an answer, however, yes the tutorials are good for teaching the basics, but to actually be proficient at the game is another matter. There is quite a lot to actually being able to play the game well, but hopefully the process of learning is pleasant enough. I would say that there is a considerable learning curve here.