Atlantica Online is a Free to Play / Item Mall based MMOG by NDOORS Interactive. The game features traditional JRPG-styled turn based combat (a'la Final Fantasy) and allows players to assemble groups of up to 8 player-controlled mercenaries to utilize in battle.

The game was originally launched in the US in 2008 after experiencing considerable success in Asia. It's a multiplayer online turn-based strategy game where you hire and outfit mercenary armies to do battle in your name, earn experience levels and loot, and maybe buy a few in-game items with real-world money by way of microtransactions.

US Official Site: http://atlantica.ndoorsgames.com