In video games, choice is often a lie. Perhaps it's a case of art imitating life too closely, but whatever the reason it's usually a good idea to do the right thing. Overlord tries to buck this trend by offering incentives to follow an evil path, but after playing a while you find just as many incentives to be good. At the end of the day, the choice to be good or evil isn't really a choice at all, since the outcome will be the same every way.
So enough about that, how's the game? Well, the graphics are good but not great. The sheer amount of action on screen at any time tells you it's next-gen, but the plain colors and animations sometimes make you second guess it. The music is good and the sound effects are funny at first, but both get repetitive after a while. The overall gameplay is handled well, directing you minions (the main means by which you manipulate the game world) works well with the 360 control pad, but a mouse would make the whole thing a lot easier.
Overall, Overlord is a decent game and definitely worth a rental. It's different than anything you've played this year, but that's probably becuase one game like this is enough.