Like Niko Vasileas said, we don’t have deciphered writings from the Minoans, so we don’t know for certain much of anything. But:
- We know the Greeks were Indo-European, and the Minoans likely were not.
- We know much of Greek mythology has Indo-European content in it.
- We know some things about Minoan religion from their sculptures and frescoes: Minoan religion. And they don’t look Greek.
- We suspect there was at least some Mother Goddess stuff going on in Minoan religion. Or at least a lot of stuff involving boobs and snakes.
- We know there were some faint echoes of something in later Greek mythology, including the Labyrinth and the Minotaur, but also the infancy of Zeus in Crete.
But no, the pre-Greek Cretans would have had their own mythology. The Dorian Cretans would have had Greek mythology, though maybe with some admixture. The people speaking Eteocretan language a thousand years after Minoa may have had Greek mythology, or they may have had syncretism: there is a bilingual Eteocretan–Greek inscription (Dreros 1) in a Delphinium, a temple of Leto, Apollo and Artemis.