The Bridge of Eldin can be said to be a basic stage upon first glance. However, this is far from the truth. There are no extra levels other than the bridge itself meaning all the fighting will take place on one plane. However, it has several internal quirks
From time to time, King Bulblin from Twilight Princess will come racing along the stage, hitting anyone in his path, but will also drop a bomb in the centre of the stage. This bomb cannot be thrown or picked up and essentially takes out the middle part of the stage creating a massive hole segregating the action. After a short amount of time however, the bridge is repaired by a Twilight Portal dropping a piece of rock that conveniently fits into the hole.
Also, occassionally Bokoblins and other Twilight Princess enemies will appear to cause some damage to anyone they come in contact with.