From the press release:
“More than four million players around the world survived the ordeals of the zombie infestation on the once beautiful island resort of Banoi. Our group of survivors thought they had finally found a safe place away from Banoi to escape from this terrifying nightmare.
They were wrong.
Featuring character-import options for fans who want to carry over their original saved games, Dead Island Riptide is the thrilling next chapter in the Dead Island universe. Co-op has never been more important as Dead Island Riptide players band together to defend new, key territories in water-soaked tropical locales against hordes of never-before-seen zombie types. Also, a new playable character class, fresh gameplay mechanics and drivable boats plunge you ever-more into the depths of what’s really lurking behind the deadly zombie infestation….”