Game Tatars refer Golden Horde and Timurid Empire. Golden Horde consisted of Turk people and Mongol Rulers. Timurid Empire is Turk both ways.
Historically “Tatar” named people are Turks but they are bilingual people and they speak Turkish as well as their original language different from Turkish. On the other hand, European and Islamic word used “Tatar” word in order to describe Mongols. Even Ottoman Turks used “Tatar” as Mongol like Tatar Genghis, Timur etc. Both European and Muslims thought Turks and Mongols are same race but it is definitely untrue. Nowaday Tatars are descendant of Kiphcak Turks. They are named Tatars only because their ruling class was Mongols.