Palaic language
This is the language which we don't know much about. Palaic was a branch of Hittite spoken in the country named Pala, north to Hittite state. It was influenced greatly by the native population of Anatolia, Hatti people, and that's why was constantly losing its Indo-European features all the time until it became extinct in the 9th century BC.

Palaic was written in Cuneiform and didn't differ greatly from Luwian of Hittite. A distinguishing trait of its phonetics was very frequent mutation of -t- into -r- between vowels. It is called rotacism and is widely known as a common Latin and Umbrian feature. Now we know it happened also in Hittite, but rarely, and in Palaic, which makes some linguists think about the appearing of rotacism already in Common Indo-European times.

Endings of nouns and pronouns in Palaic were not too fashionable and often are not used - the matter that makes us think it was moving towards analytic stage under the influence of non-Indo-Europeans. For example, genitive singular of nouns usually was replaced by derivatives with -k- suffix. Together with Luwian language Palaic was already about to become an agglutinative language and leave Indo-European flexions. But the time has come, and the language disappeared.

It is interesting that, unlike Hittite and Luwian, Palaic did not give birth to any late Anatolian language. The lands where it was spoken were later inhabited by Phrygians.