I think the simulation aspect is higher than almost all other games out there - there are multiple different types of ammo, the cars have separate engine sizes, etc - but I get what you mean with survival. A water purifier and a bee hive will keep you full of food, and once you have shelter there’s no more drive to survive.
Once rotten meat can’t be cooked, it’ll be harder to create enough food to last the winter, but I don’t think that’ll add much difficulty. By the time you’re stocking up a pantry, food isn’t really a problem. Stocking up is just to save time from hunting, which is fairly easy. One water purifier and 100 batteries goes a long way for water. Looted MREs and canned goods can easily get me to that point. Finding the water purifier is just luck really.
Roaming mobs could make shelter less reliable, especially if they could smash walls, etc. Would be a hard balance to get between too often, too powerful, etc. Currently a moat seems a bit too effective.
Fighting for survival is fun, but it becomes tedious in the end game. The end game of super soldiering yourself and making a death truck is also a fair bit of the appeal to me, and having to go hunting twice a day would just be annoying. What survival elements do you think would bring the most fun in?
Personally, I’d like to somehow see more weather effects beyond having to stay inside or downstairs. If cold became more of a problem ala Unreal World it’d be quite interesting, but I can see it becoming just another random weather occurrence that stops you going outside.