It could work, and it would definitely be more fun if it could include a cooperative mode with separate players working with separate powers. But I'm still not sure what kind of specifics would be in mind. For example, what would kind of twists could we introduce into the story? What is the reason the squad is going out against said enemy? Personally I'd like to see more ideas put into the idea before I'll give it full support, because this might degenerate into a typical space marine game. The Dead Space series was fantastic because the protagonist was not a space marine, rather an innocent bystander thrust into an unfortunate situation. It's more of an engaging story when the main character is forced to do something they don't like.