This 4X game has gone through quite a ride. I tried it out when the base game was released and frankly, it sucked. Since then, it's been through Three(!) different companies and development studios and has picked up three expansion packs, the most recent being "Argos Naval Yard", released yesterday. I have not put a lot of time into the expansion and the new techs it adds, but that scarcely matters.
This game is the spiritual successor to MOO1. I say MOO1 and not MOO2 because like MOO1, it focuses less on planetary structure optimization and more on overall economic strategy, research, ship design and fleet combat. Economic strategy and research are a few planetary sliders that you rarely touch and one overall one that you adjust almost every turn (Savings<---->Research). Ship design is simple but deep, relying on 3 different ship sections (Command, Mission, Propulsion), and 4 different weapon mounts (small, medium, large, special) which gain expanded options through a MOO/CIV-like research tech-tree.