Two Worlds seems lie the obvious option.
But when I consider that most AssCreed game have had 10x the developers, 10x the budget (at least), and end up with a map full of spam copy paste "activities" that are an insult to the intelligence of one of pavlov's dogs - I think Ubisoft wins here. To do so little with so much.
Also great ideas, gfx, and monster, but HZD comes close to worse in terms of a totally empty openworld that is little fun to explore or traverse - with next to no reward for exploration, and some of the worse collectables ever devised - collect coffee cups for tedious text exposition