5. Weather Systems
Weather Systems could act as more of an addition to Hardcore mode, or even be added to the easier modes at a lesser extent. When I am out under the radiated sky, I want to feel real-life consequences and effects of fatigue, as this video game is about as close as I'm going to get to experiencing nuclear fallout. While it's cold outside, my character should begin to shiver because their clothing or armor is too thin, which in turn effects their accuracy while they shiver, or perhaps they end up succumbing to hypothermia and pass out for a set amount of time (similar to the "wait" system where a few in-game hours are a few real-time seconds). Who doesn't want to see real-world simulated post-nuclear fallout weather systems such as acid rain or the nuclear twilight without actually having to live through it?