Edit: I also didn't expect them to use the people who did voice acting for the game, but it's bizarre to me that they decided to get Jen Taylor to voice Cortana but didn't decide to cast her as Halsey. Would have made more sense to just have the lady who played Halsey voice Cortana as well, since Halsey modeling Cortana after herself tells you a lot about her character and her overinflated opinion of herself.