User blog comment:Master Sima Yi/Assassinews 05-08-'14 – Assassin's Creed: Rogue announced/@comment-5174994-20141125225313/@comment-4829046-20141126134714

Actually a synonym of beat is "conquer". In this instance, you literally make a conquest of the game. The game has pretty much nothing else to throw at you except glitches, unknown gameplay mechanics and Easter eggs that you missed.