10. An Established Health System
Regenerating health should just be something that comes as standard in any game where exploration and large amounts of time between checkpoints is a key factor. There's just nothing worse than barely scraping through a firefight, only to have to amble on, knowing that anything from a Raider to a Bloatfly will finish you off within seconds. Now, I'm not saying it has to be as quick n' easy as something like Halo, where standing around makes you good as new, but both The Witcher series and even Fallout New Vegas implemented regenerating health bars that came with key stipulations. Having your HP come back a few points every second is just enough, especially if it's something you can upgrade and track, giving you more confidence to stay out in the Wasteland and explore to your heart's content. There's also the possibility of healing wounds, Far Cry-style, as although you could argue having the option to manually get you out of your near-death state ruins the immersion and risk factor somewhat, it only needs to do so to a point where you stand a chance in the next encounter, not necessarily a full refill. Point being; it's annoying having to make a save knowing that you're one shot away from death, and anything to remedy this would be brilliant.