Europa Universalis 4
Managed to snag one of the hardest achievements.
Played as Byzantium which in 1444 is small, weak and about to be eaten by the Ottomans, but mercenaries, 40 loans and on the brink of bankruptcy later I managed to take back all of Greece, then eventually restored much of the Byzantine Empire and wiped out the Ottomans in the process.
Did want to continue for a Roman Empire game/achievement but Austria was OP as f**k in this run, annexing Burgundy/ Netherlands, Bohemia, Hungary and Poland-Lithuania... f**k this shit I'm out.
But yea I'm happy with my Basileus achievement.