how about having 2 playable characters, each having different abilites (like in the old Resident Evil games, and like in some of the DLCs), one could have a sneaky, Isolation like story, one could have a bit more action in it. eg. Amanda and a marine, colonial marshall, but i want pulse rifle or some sort of that, heavy weapons, no more of the shotgun wont hit the alien bullshit....because that was just that