It's a bit early to judge but this creates many plot holes. For example how are they going to have plasmids seeing as they come from a sea slug. Also I'll be pissed off if it turns out that rapture is just columbia fallen into the ocean. Andrew Ryan was supposed to be an extremely determined and insane genius who went to rediculous lengths to build Rapture. His character would be ruined if it turned out that Rapture just fell from the sky. If somehow IG ties up the story well, the change in setting could be a breath of fresh air for the franchise.