Well Julius Cesar was supposed to receive command of Cisalpine Gaul and Illyricum. And his plan for winning glory (and money) was provoking a war and conquering in North East direction - Balkans and perhaps with his usual impetus toward Central Europe, perhaps as far as today's Ukraine.
But a person that have been nominated for Transalpine Gaul command Quintus Caecilius Metellus Celer had died unexpectedly and his imperium have been passed to Julius Cesar.
Now imagine that Julius Cesar and his legions had conquered Central and Eastern Europe while Western Europe had been left alone. And Augustus and further Cesars will continue in this direction.
Depending on how far they got, and there's more than a good chance that the Parthians may have destroyed any army sent against them. If not, then the Romans would have had to face the steppe horse archers a few hundred years earlier than otherwise. And that would never be easy.
Without Augustus as the first emperor who knows if Rome would have lasted nearly as long as it did