first time I played I was not sure what to expect, got in a back and forth stalemate with the Rus until the Danes came out of nowhere. Victory in 454 turns.
Second time I played, expanded outwards fast until I saw an enemy, fortified the islands that they could see and built siege ships rapidly. Victory in 164 turns. I noticed on this second run my tech level was advancing way faster than my enemies, since I took many central islands and kept them from expanding. They never even upgraded their warriors to armor, let alone get siege ships that could attack me back.