Agartha, from my under-the-works demo guide

[moodgiesanta]

I just finished an Agartha game and after several games of getting killed with other countries, this game instead I obliterated the enemies. The main reason is the Troglodyte. Massed Troglodyte attacks pretty much kill anything size 2 and under. They are also very easy to build en masse even in low resource provinces late game when you have tons of money.

Another *huge* advantage is the amphibiousness and the ability to build underwater but that's been mentioned.