This is a review for the expansion: Raising Hell. For a review of the original Overlord, please reference my steam review at http://steamcommunity.com/profiles/76561197980576540/recommended/11450
Raising Hell's storyline takes place after the events in the original Overlord. Abyss Gates are spotted in each of the lands that you have previously explored and present a twisted, more hellish version of each area. The seven sins of hell come to mind when playing through these areas. Your goal is to go to each Abyss and take control of it. You will also find moulds in these zones to create new and interesting equipment.
The unique armor and weapons added in Raising Hell present new abilities that otherwise would not be available to you; however, the new equipment is woefully underpowered. If you already have a full set of Arcanium gear, you're better off ignoring these new items.
Although the expansion adds much appreciated content to an already outstanding game, it does little to nothing to fix the flaws of the original. If you enjoyed the original, this game will be well worth your money.