User blog comment:Willbachbakal/My BioShock Sequel Idea Dump/@comment-175.139.62.248-20130826141158/@comment-1330314-20130830214709

Again, Call of Juarez did not invent co-op either. The protagonists in the co-op campaign are also equally important, and are meant to both critically influence the storyline. Though both players have access to the same abilities, there should be a sufficient amount of choice so that they'd end up playing with two completely different kits.