Play Dead Island - Definitive Edition at least 28 days after starting it for the first time.

Found a copy of Gangsters Monthly

Completed "Sarah"

Won the race

Completed "Molotov Party"

Found a 'Gangsters of the United States' cigarette card

Completed "An Offer You Can't Refuse"

Reach the highest point in the castle, the Headmaster's upper study

Complete all side quests

Win the House Cup

Win 100 matches.

Breed every type of beast

Defeat enemies in all battle arenas