Really interesting concept. I am failing miserably though. I do feel that 'C' for calling daisy is annoying, because in games it's quite frequently crouch. Might be personal of course, but I keep pressing C when I want to crouch and hide, usually when I'm panicking :-)
Also feel that shift should be running instead of walking, so you should be walking by default. Unless that's part of the experience, making it a bit harder.
Also what would be really beneficial is to add surround sound. I find it quite hard to exactly pinpoint where the sounds are coming from.
It does sound like I just suck at your game, right? ;-)