The markers are looking for a personal response to the play. SO critic quotes aren't necessary to achieve full marks. HOWEVER, both my teacher and tutor recommended that we include 1-2 quotes from a well renowned critic e.g. Coleridge, TS Eliot, Hazlitt, Nietzsche etc. For instance, you could say "I agree with Coleridge's interpretation that..." or "I disagree with Freud's psychoanalytic interpretation and instead believe that..." It shows you've done a bit of extra research as well.