See the dialogue Timeous where Plato talk about Demiurge. Platonic Demiurge failed to create the perfect world - the perfect image of the perfect eternal Forms, because he has to work what is given to him - the imperfect changing matter.
"The world of Becoming, which is constantly changing, can never completely imitate the unchanging Forms which are the Models for sensory objects. The Demiurge is constrained by the materials he has to work with. Nothing in this world is Everlasting or Unchanging. Eternity (the Form) can only be imperfectly mirrored in the physical world by something which is itself changing. The Demiurge, though constrained, tries to produce the most perfect copy that he can." (See the chapter Plato's Universe of Evolution of the Concepts of Space and Time by Michael Bradie and Comer Duncan.
Now to discover the Maker and Father of this Universe were a task indeed; and having discovered Him, to declare Him unto all men were a thing impossible. However, let us return and inquire further concerning the Cosmos,--after which of the Models did its Architect construct it?Was it after that which is self-identical and uniform, or after that which has come into existence; Now if so be that this Cosmos is beautiful and its Constructor good, it is plain that he fixed his gaze on the Eternal; but if otherwise (which is an impious supposition), his gaze was on that which has come into existence. But it is clear to everyone that his gaze was on the Eternal; for the Cosmos is the fairest of all that has come into existence, and He the best of all the Causes. So having in this wise come into existence, it has been constructed after the pattern of that which is apprehensible by reason and thought and is self-identical.