Simple premise... A stripped down game mode made to be more challenging and realistic.
It could be done sufficiently well only by tweaking already existing game settings.
For instance:
-Less warning calls
-No spotting
-Better animal sight
-Longer fleeing time
-Lower animal population
-Less effective callers (for most if not all animals)
-Shorter animal zones (drinking only for half and hour or so)
-Animal zones dont show up on map
And animal zones cover a larger arean, currently its about 100m²
Feel free to add more suggestions, this is just a short list, since i dont know how many people would even be interested in such a different experience. But surely it cant be a hard addition to implement into the game, right?
(Also add option for higher FOV while aiming down sights)