The US version changed some plot details, most notably in how many kings are involved: while the Japanese version mentions three kings named Kells (ケルス), Rude (ルード), and Phillip (フィリップ), the English version changed nearly all of these to Edward (the exception being a mention of Kells near the beginning of the game). As the story is already extremely cryptic, this was likely done in an attempt to make things less confusing.
Before the save point in the Forgotten Region of the Human World, there are multiple locked cells which can be opened with the Brass Key. Near the save point is an empty cell that appears to have nothing of note inside. However, if the player positions the camera correctly a hanging corpse can be seen hanging out of bounds through the wall. In a Japanese trailer for the game, a similar location can be seen with a corpse hanging inside a cell which gets unlocked so it's likely that the corpse was moved out of bounds in the final version to avoid players seeing this scenery.