Burial at Sea

Bioshock Infinite was fairly unique in that it was entirely self-contained with room for discussion, but with plenty of opportunity for DLC. The idea of multiple universes isn't a new one, and it always opens itself up to certain issues, but it did mean that Booker and Elizabeth could end up appearing almost anywhere. So, of course, they ended up back in the underwater city of Rapture. It was an easy way of impressing fans, but it's questionable whether that managed to pay off.