First I just wanted to say that I've loved the civ series ever since civ 2.
Since farmville is really old news now I was a little surprised that civ world would essentially be just another copy of it. Ok I wasn't really surprised but I was expecting more.
Specifically there are major things missing. The Civ World game doesn't actually end. It just goes on and on. There is no real way to lose, other than by stats. Stats don't have meaning to me. Seeing my cities burned down or my borders shrink matter.
I would rather pay upfront for a better social civilization, than play a free game that makes money from people buying resources earlier.