I've always found Call of Cthulhu to be one of those games that may never be released despite the cool premise and some awesome game footage. When you read about features like this it's hard not to be a little bit sceptical.
Due out in Q3 or Q4 of this year for the Xbox and the PC we'll soon get to see if any of this pans out. You can get more info, screens and an interview over at Gamer's Hell and decide for yourself if half the stuff they talk about will actually work.
What you see on your screen is exactly what Jack sees – there are no icons, no ammo counters or health gauges. If you run for a long time, you get fatigued. If you fall down a flight of stairs, you might break a leg. If you are cold, you shiver. If you are injured, you stay injured until you can improvise some first-aid – there are no magical health rechargers or armour packs lying around. All of these factors go together to provide a highly immersive game environment.