The label assigned to the book has become a source of controversy, in particular due to the blend of hard science with romance in the Romeo and Juliet tale of love between the scions of two empires. Some romance readers have said the book doesn't qualify as romance because it is, first and foremost, a story that emphasizes science fiction, one where the two lovers are separated for a third of the book; whereas some science fiction readers have criticized the extent of the development of the love relationship and emotional lives of the characters.