Mine is a little over the top. Make a survival game, but I mean over the top.
Crafting: Electrical designing (e.g. gathering solar panels , Batteries, light bulbs, water power generators by rivers , etc)
Hydraulic (e.g. collect cylinders , filters , hoses , power packs) so you can break down military bunkers or even make a hydraulic operated door or alterations to your vehicle.
Building (e.g. collect concrete, get tar to increase walking speed around base, Wood for simple building , sheet metal for easy roof, slate for roof)
Farming (e.g. plant seeds , grow, capturing animals, Milking cows , etc...)
Scavenging: If a building has no power you have to get batteries and get wire to rewire the electric doors.
Weapons: You actually model your weapon, like getting a steel rod and putting a Saw blade in the end of it and hook that to the side of your car. Or like firing your weapon should really I mean really be your last resort, if you do fire you get damage on the weapon which would require you to really disassemble the weapon clean it out and perhaps replace parts.
Don't know I want something insanely indepth, not this easy stuff that is available at the moment. The only thing coming close to this experience is Project Zomboid, IMO it really has a potential for success. They literally make you get a pot, get water with a bottle, boil the water then put the noodles then you can eat.