A game where, in the manor of the Stranded series (or, at least Stranded II, the one I played), loot is obtained from the environment, rather than as random drops from enemies, and all items a player can use need to be crafted by them. Some resources would need to be obtained from animals and enemies, but the challenge wouldn't be in finding a bear with an intact ass, it would be hunting down the bear in the first place, with some sort of tracking skill or ability. Likewise, other resources would be things found where they would logically occur; if you needed wood, you would look for a tree rather than in a chest.
Some resources would be guarded by enemies, but it shouldn't be possible to kill every enemy so that a player can safely gather resources; enemies will just keep on spawning. If a player wants to make an area safe, they should have to set up some barricades and traps to keep enemies out. Enemies should spawn in the middle of a player's camp though; they should either spawn out of indestructible or near-indestructible spawn objects.
There should be some enemies that need to be killed in a certain way. Also, there might be some unique "boss" enemies that don't respawn that need to be kill for some reason. The nature of how certain enemies can be killed, the existence of specific bosses, and the contents of dungeons should be something a player can information about in-game without having to use trial-and-error, so the can prepare for upcoming challenges. Well, maybe sometimes the player should have to go in completely blind, but in those situations it should be possible to run away if things get rough. And if a player doesn't bother to look for hints about a dungeon or monster, the game isn't going to just give it to them.
There should be various useful locations like rivers or libraries (for research) or laboratories that a player would want to either build a base around or have easy access to. The player might need to hire NPCs to guards some locations while they're away, or at least set up fortifications and some method of entry. Various transportation methods might need to be set up to travel easily between different locations.
If there are NPCs, any trade done with them should be on a bartering system, and they should have limited supplies and needs, or maybe ones that change as time goes by. The should perhaps take resources from the environment like a player, so their supplies are based in reality. If their goods have actual, physical presence outside of a trade screen, then a player should be able to steal them, angering their civilization and making the player an enemy. Nothing in this paragraph is essential.
I guess I basically want a game where I can hunt werewolves with silver bolts fired from a crossbow I made myself out of wood I got from an actual tree, and then be able to skin that werewolf and use it's pelt as a rug in a fort I made myself.