What you download is not a demo, it is the full game. There is, however, a level limit at 6. When your character reaches level 6, you can start a new game or, if you decide you like the game well enough, go on and buy a license online.
War has come down on Calradia and war attracts its own bunch of misfits. Mercenaries, cutthroats, knights and adventurers flood into the land looking for employment, fortune and glory. But war is a harsh master. It gives away death and grief to the lot, fortune to a chosen few, and glory, wise men say, to none. Still, men ride to war, for one or other reason. Some because they are looking for thrill and excitement, some because they are desperate and know no other way.