Overlord has some good ideas. and it is pretty,even on standard def, but dumb things like no camera control mar it alot.
it's almost like the game is fighting you as much as bosses from time to time.
that aside the concept is novel and implemented well. all the mechanics are there and the game has a fantastical design on par with the better lord of the rings games....if you can manage to see it.
it's worth a rental, but little more, unless you're really an evil overlord yourself.