If you've played City Life or Sim City Societies, here's what changed between those and Cities XL:
-Zones are back, no more placing each individual buildings
-Auto road for all zones, although there is an option to just place a single square zone without roads
-Zones don't have to be perfectly square, they can be just about any shape you want
-Less micromanagement, more macromanagement
-Very informative displays and notices
Basically, even though the online aspect of the game is long gone, if you like city-builders, you will like Cities XL. It's $5, go buy it.