It plays much more like a strategy game than a sandbox. Commanders can be permanently killed and cities and towns and forts can be permanently razed, so you must pick your battles carefully. Your goal is to help your faction control Middle Earth. You are a commander in one of three factions: the Free Peoples (elves, dwarves, hobbits and men), Sauron (the White Hand orcs, goblins and trolls) or Mordor (the Men of the East, orcs, and ring wraiths).
Last Days of the Third Age - a Lord of the Rings mod that plays completely differently than the base game. I've played through 3 times and they all felt different because of how I built my character, army and alliances. A new fantasy world with more quests, balanced factions and better combat.
Prophesy of Pendor - an absolute must-play.