They're basically selling the same features that were in civ 4 but play a bit differently and should of been in the base game on day one. The biggest feature that was missing was Diplomacy. Basically this is a patch you have to pay for. This is a horrible business practice by 2k. But it doesn't matter because people will buy it anyway. People don't care that games come half finished, they don't mind paying more money for DLC, it's no wonder why publishers pull this stunt all the time.