One of the most addictive strategy games I've ever played! If you only buy one strategy game this year make it this one!
The tech tree is huge... and for those who played the first installment of Galactic Civ it has been streamlined into different research categories so it is easier to focus your research depending on your preferences / what type of victory you are going for.
Another awesome addition is multiple weapon and armour types. You can now have lasers (countered with shields), missiles (countered with point-defence), and mass drivers (countered with stronger hulls) where each defence functions to full capacity only against it's respective weapon type. This can lead to intense research races to rapidly change your armada's weapons and defences to counter your opponents.