The Hobbit: Armies of the Third Age is a new web-browser-based game set in Middle-earth. Developed by Kabam Games, the idea seems to be to build your own little kingdom and command armies as you attempt to claim your own little bit of Middle-earth.
You can choose to play any one of three races: Dwarves, Elves, and Orcs, and you can recruit unique heroes to do your bidding.
I'm not much of a gamer, but I was able to build up a nice little elven village quick smart and take out a low-level Goblin camp pretty easily. Perhaps the difficult escalates later on. Oh, and it's free to play.
The developer blurb:
It is a time of great turmoil in Middle-earth. Elves and Dwarves, long at odds over ancient slights, are now on the brink of war. Meanwhile, vicious Orcs and Goblins plot to overthrow the other races and burn their kingdoms to the ground. Take up arms alongside the greatest heroes of the Third Age to create your own kingdom within Middle-earth. Build an empire of Elves, Dwarves or Orcs and partner with thousands of players online to crush your enemies and defend your realm. The fate of Middle-earth is in your hands!