Complex sentence: Unlike "Snow White", which was a short story that the writers could expand and experiment with, "Pinocchio" was based on a novel with a very fixed story, therefore the story went through very drastic changes before reaching its final incarnation.
Split into simpler sentences: Unlike "Snow White", which was a short story that the writers could expand and experiment with, "Pinocchio" was based on a novel with a very fixed story. Therefore the story went through very drastic changes before reaching its final incarnation.