The Ottoman Empire didn't form until late 1200's, early 1300's. A lot of the factions you'll probably get to play aren't even around anymore. Since the game starts when Rome is made a Republic, so 500-400 BC, you'll start at nearly the very beginning and will have to conquer everything, so this will include Hispania, Germania, Britannia, Gaul, Illyria, Macedonia, Armenia, Dacia, Thrace, Syria, Parthia, Egypt, Carthage and Numidia. What you know as the Ottoman Empire didn't even exist at this point in time since the Turks were nomadic. We might see the Achaemenid empire, or Persia, which will probably be the closest to the Ottomans. Like alooy said, you will want to play Empire Total War if you want a faction that is 100% Ottoman. Medieval Total War will have the Seljuq Turks, which were the precursor to the Ottomans.