The Myceneans were likely ethnically Greek and seem to have spoken an early version of Greek. I have not seen anything to indicate if the Minoans (who were distinct from Myceneans) were ethnically Greek, but their language does not appear to be Indo-European. If it were, it would be easier to translate. If the Minoans were ethnically Greek, that suggests that there were a population of people on the mainland and on Minos that spoke a non-Indo-European language and that that language was larger displaced on the Greek mainland by Indonesia-European immigrants who transferred their language to the native people and that evolved into the various kinds of Greek language.