A follow-up to the original Overlord, Overlord came out in 2009, two years after the original. The sequel adds a few new features in terms of gameplay, fixes a few problems from the first Overlord, and continues the plot, albeit only slightly. Unfortunately, it brings with it new problems and glitches, has even worse multiplayer, and generally has elements that are tacked on and feel like an afterthought. A pretty average game that will appeal to some and turn off others.
From a graphics standpoint, the game improves a lot from the original game. Still, the game isn't that pretty, and I would even go so far as to call the game downright ugly. There are also a fair bit of visual glitches where colors don't always load or load in splotches, and occasionally the textures are wrong. Lighting effects are also pretty bad, and clipping issues are somewhat prolific. None of these problems are game-ruining, but considering that over, much better looking games came out around the time, it's very lackluster.
The camera, like in the first one, follows the Overlord when not guiding the minions. Unfortunately, just like the first one, controlling the minions in any way has the camera follow them from the standpoint of your Overlord. This makes for awkward and difficult camera control if you just want to look around without telling your minions to run off somewhere. It isn't impossible to shift the camera, but it's still a really poor mechanic that the developers really should have reconsidered.
Sound effects and voice work are on-par with the first game. That fact is neither good nor bad, but instead just winds up as forgettable. Returning characters have their old voice actors, and it's amusing when you club a baby seal. (If you object to clubbing baby seals, this game probably isn't for you.) Those aspects aside, you probably won't find anything remarkable.
Gameplay-wise, they brought back the old system and added some new features. Your minions can ride unique mounts, you can assume control of one of your minions, and you can mind-control some NPCs to act as meatshields and disposable soldiers. You'll need the mounts to gain the edge in battle and solve some of the puzzles, and the same can be said about assuming control. Mind-control/mind-overload are both linked to some achievements, but you won't really use them for anything else. These features bring with them a few glitches, and controlling mounts can mess with your overall control in battle.
The puzzles are a little more involved, but not still particularly difficult. As mentioned before, the mounts throw in some additional elements, so the difficultly and tediousness are raised in equal measure. Even with these additional options, given the low difficulty, these puzzles just grate on yours nerves more than challenge your intellect.
As for the story, it's nothing special. Much like with Knights of the Old Republic and its sequel, there isn't any way for Overlord 2 to beat its predecessors. They try to some extent, but they also fail. It isn't a bad story, but it isn't anything more than average.
The multiplayer is, honestly, completely tacked on, with no real thought or effort put into the feature. A few achievements are tied to the multiplayer, and again, more tedious than fun or interesting.
At the end of the game, the game is both better and worse than the first game. It's still fun, especially if you enjoyed the first one. After more than four years since its release, it would also be pretty cheap. That said, you'd be better off renting or borrowing the game from a friend. It won't be on many people's Top 5 list, but it won't be on many people's Worst 5 either.