Shadow of Colussus is a prequel/sequel
It's a prequel because it tells the story several thousand (correct me if I'm wrong) years before the story of Ico and it's a sequel because it's basically the spiritual successor to the game.
But I think the rush job treatment kind of applies here to pokemon as well, considering how crappy the soundtrack and storyline (at least IMO) came out. At least that's what I think of Diamond and Pearl anyway.