I've never understood publishers fears over spy games. The Bond and Bourne films are some of the highest grossing in cinema history, 24 is one of the highest rated TV shows of the last decade and yet publishers are always worried that a spy game won't sell?! Idiots, people love spys and an RPG that allows you mould your own play style and captures every part of the experience would sell massively. Even Alpha Protocol, flawed gem that it was, managed to shift units despite being badly advertised, buggy as hell, poorly reviewed and coming from a B grade developer.
You must fear your target, yet respect it, like the crocodile respects the helicopter.