Appetizers are not covered. You're entitled to a main course and a dessert and a non-alcoholic beverage.
That said, items like sushi or flatbread are not necessarily "excluded" but if you wanted one covered by DDP you would have to order it as your entree. This isn't considered the best DDP value, because CG costs 2 credits and the entrees are much more expensive than the flatbreads or sushi.