A great game with a lot of issues.
I have found the multilayer aspect extremely rewarding as I share my region with a couple of my buddies, its great sharing resources and giving each other a good start. Then working together on one of the great works, like the solar farm or space center. It's great building different types of cities and either sabotaging your citizens lives or building lots of parks to keeping them happy. It's also incredibly entertaining when you get a zombie outbreak and you can watch as they annihilate most of your population.
One real problem with the game play itself is how small the cities are. It's great building multiple cities that work together, but It can be frustrating running out of space especially when nearly all of your buildings are already high density. Its a shame considering how you could make enormous cities in Simcity 4. This is something that really should be addressed as it puts a limit on how long you can play the game for. It gets to a point that all you can do is leave your old city and start a new one. You soon end up just making blocky cities that focus on saving space as opposed to creating something aesthetically pleasing. It's a great game, but in it's current state it causes a lot of frustration.