Feudalism III is the third chapter in the series, and the most built-out: a broader roster of classes, a proper skill system, and a campaign about taking your homeland back town by town.
Where the earlier games were mostly about numbers and gear, this one leans on how you compose a party. Melee, ranged and magic all pull their weight, skills unlock as your characters grow, and the weapon you hand someone changes what they can actually do in a fight.
Originally released in 2013 and playable free in your browser here — no download, no plugin.