It's not my idea, I should say. I can't really remember where I found it, but it was on a Facebook discussion about the different 40k video games out there in the world. To bring it down to it's brass tacks, the idea was this: It would be a survival horror in which you control a lone Imperial Guardsman after their ship was attacked and taken over by the forces of Chaos. Your goal is now to find some way off that ship alive, while there's still some sort of chance. There were some finer details, to the point where your character would also have to fight the influence of Chaos and the idea of an expansion where you'd do the same thing again on an Inquisitor's ship after he suspects you of being tainted by chaos. Whether or not those are good idea or not can probably wait, let's discuss this idea.