I think I got a copy of this about 5-6 years ago, although I'm not certain. Much like Diablo, you were running around an open area and fighting monsters, I think primarily with melee weapons. What was a bit different was that you were defending a village, and gathering resources for it at the same time, maybe also building buildings and designating people in specialist roles (blacksmiths, crafters, etc). You could pick from a variety of starting profiles (it kind of mixed races and classes from the traditional RPG setup so you could be an Elf or a Warrior or a Peasant) that gave you various perks. I have this vague recollection that it was not quite finished at the time I got a Steam key for it, and new features were still being added.
It was 3D graphics, I think, although I think it maintained something like an isometric angle looking down at the character. I remember that one of the annoying bits in the game was that it wasn't uncommon for enemies to be shooting at you from just outside of your viewpoint. I don't remember if there were other maps or dungeons to explore. The part I remember was kind of an open field with some trees, rocks, and bushes breaking things up. The enemies tended to stay in their sector, maybe unless they were raiding, and I think you may have been told how many of them were still alive in the sector, maybe with a generated name like "The Thorny Hold of Hobgoblins" although I might be channeling Dwarf Fortress there. The sectors did not have a physical border to them, no idea if they triggered anything in terms of loading.