A nice update from the previous titles in the series, this one new graphics and mechanics to make the experience new again. The campaign itself is very enjoyable as it takes place over several ages where you begin in the colonial time and progress to new periods as the campaign progresses.
Some of the new mechanics involve the economy, as you can now select specific commodities to import and export, granting you the ability to buy low and sell high, while also allowing you to target industries you'd normally lack resources to develop. Other changes also include military buildings also producing different kings of military units (e.g., Army Bases result in 3 tanks per base), which makes military expansion more strategic compared to the previous interations.
Also with this version is the inclusion of Online Multiplayer, which unfortunately, I have not been able to participate in.
Should you buy?
Very much so. This is a fun macro-oriented city builder that provides an enjoyable experience. If you are a person who is compelled to buy DLC, then I suggest waiting for sales or special editions that bundle all the DLC together.