By now, there's only one server based on EU-France. We're working on opening US servers, translate the all game in English and adapt payment system for Desura.
You'll be able to purchase and play 4 the King on Desura in a couple of weeks.
You can still visit www.4-the-king.com to have some news, but everything is is french for now. You should wait for Desura release before purchasing the game ^^
