What impact did Crete have on Ancient Greece?

As Toby Williams said, significant in pre-Classical Greece—after all, the Mycenaeans got their writing system from the Minoans, and there are echoes of the old Cretan dominance in the myths around Crete.

In Classical times, not much at all. A couple of philosophers (including Epimenides and his paradox), but Crete was a backwater. That continued even into Byzantine times: Andrew of Crete  is all I can think of for cultural impact on Byzantium. It was only under the Venetians that Crete had a significant cultural impact on the Greek-speaking world (including art as well as literature).