Harpoon a killer whale.

Recruit 500 crew members.

Complete present day mission 2.

Swim a total of 1 nmi.

Earn 50,000 reales.

Complete 25 Abstergo challenges.

Find a buried treasure.

Kill a guard ringing a bell.

Stay awake until you collapse at 5AM.

Complete 'Grand Finale'.

Complete 'Batteries Not Included'.

Do everything you can for Kinzie -- Quests, Loyalty Missions... everything.

Purchase all Super Power upgrades.