On their website, there used to be a summary of what it was supposed to be, but that has since been removed. From what I can recall, it was a full game with missions and goals that followed a fictitious plot surrounding a robbery and a flee to NYC. It began on April 10th and ended with the sinking (your goal was to survive with all the evidence you gathered). I know many people only care about walking the ship and seeing it sink, but some other people were interested in seeing the historical recreation of Southhampton and having objectives.
Me personally, I'd just like to explore the ship and see it sink (but that's where my personal interests are).