The graphics, the concept of religion, and, like Kemal said, the amount of possibilities. Although I'm convinced that people like Cartouche Bee and SirPleb will find exploits in the future.
I don't like the new combat situation: the upgrading stuff and no difference between attack and defense value. But the advantages outweigh that by far.
Oh, and what I also dislike: units movement is
slooww.