Short summary
Adding Factorio survival game aspects, requiring to look at the biological needs of the player. Further different planets with new challenges.Values
Health: is no longer "hitpoints", you REALLY have to avoid getting hurt. Health regenerates hardly and starts to decrease when falling below 50% ("blood loss"). You're getting slower the lower health is / limp and get randomly unconscious below 20% health. You can't recover health just by eating fish, but by using a "medical bay" (from your shipwreck)Poison/Illness: temporary "debuff" on health with same health effects (except "blood loss") Health drops fast about a percental value and recovers in a short time. Poisoning recovers much faster than illness. "Potions" may spend immunity and cure. There may be several different poisons and diseases, you have to research to cure, even for the med bay.
Armour: the new "hitpoints", avoiding/reducing damage of health. Consisting out of (space) suit protection, additional armour plating and energy shield. Suit/armour are getting damaged with every "hit" and only protect at 100% above 75% their integrity, so they need to be repaired again. Energy shields are absorbing damage and have to recharge like known.
Radioactivity/Pollution: permanently damaging health (curable only by med bay). Perhaps uranium mining (radioactive dust) and so on should cause damage, also smoke, which could be blocked by air filters. Solar storms / Radiation rays can only be blocked by special protecting suits resp. shelters.
Stamina: allows sprinting. Below 50% decreasing accurracy (shooting) and working speed. Recovers very fast if doing nothing. With no stamina you can only walk slow.
Air: most important, without air very fast loss of health, identical to poisoning, except that it's increasing as long the player gets no air. Some actions increase the air consumption. Artifical air supply reduces the air supply below 10% reserve which causes the stamina to drop about 50%.
(Suit) Temperature: outside the optimal range (10°C-25°C), stamina is decreasing, extreme values are even decreasing health (resp. killing you instantly).
Recovery: constantly decreasing, have to be filled by "sleep" (in a bed/habitat). A low value gives an increasing malus on stamina and leads to microsleep or even a (restful) faint.
Hydration: below 20% increasing loss of health, requires drinking or juicy fruits
Saturation: a 3 part value of nutrition: "energy" (fat/carbohydrates), "proteins" (vitamines etc.) and minerals. If one of them is below 50%, the stamina maximum gets cut, below 20% your health decreases slowly and you've got no stamina. Food rations provide always much "energy", whereby proteins and minerals aren't required in great amounts.
New stuff
Space Suit/Armour: protects against cold, heat, noxious enviroments and radiation. Plating reduces physical damage. May provide air and recycle water. The protection values and hitpoints increase with advanced suits. All suits do have a "grid" for modules, perhaps one size - advanced modules provide a bigger effect with the same size. Heat exchangers, power sources and so on are stacking to increase their effect, but may require more space resp. energy. There might be special slots e.g. for the exoskeleton, of which only one could be equipped.Air Filter: protects against noxious aerosols, radioactive dust/pollution/spores. Uses up over time, therefore you always have two of them in one slot. Could only be used on planets with breathable atmosphere.
Air Tank: module for storing compressed air => atmosphere-independent air supply
Food & plants: plants, fish and maybe other animals/meat could be crafted to food rations ("Soylent red", "Soylent orange"...
) that are consumed. Some seeds are found in emergency provision, some food can be gathered from the planet. Most can't be eaten raw.New fluids: "dirty" water/sewage (needs to be filtered to become classic water for engines and habitats), fresh air, stagnant air.
Habitat: buildings for players to rest in / sleep. Could hold air filters or require an air supply connection. Requires power to regulate the temperature. Can charge the space suit and fill air tanks. May contain a medical bay that restores the health. Might be connected with other buildings via tubes, which would also exchange water and air between them and transfers power.
Airlock: "doors" to the inside of a "planet base"/habitats etc. Require air filters or air supply. On planets without atmosphere, buildings/tubes can't be entered without an airlock.
Green House: building that produces plants/wood, seeds, soil and recycles air. Requires power to regulate the temperature and artificial sunlight. Plant growing is extremely slow, therefore you need many of them, although they are very large. Water and soil are only required to build them, no further water needed. Stagnant air and fresh air are also in a cycle.
Aquarium: building to breed fish, requires food rations, consumes fresh air and fresh water like players.
Purification Plant: converts sewage or similar to normal water. Normally you keep up a cycle of your base that doesn't lose water.
Small Solar Unit: the first cheap electricity source, 2x2, about 15 kW. Essential for planets where you can't burn fuel.
Solar Oven: stopgap furnace, 4x4 sized, can smelt ore without fuel or air by focalising sunlight. Only working in bright sunlight.
Thermal Generator: can produce electricity from heat(=>heatpipes), e.g. vulcanism. Very space-demanding compared to turbines, but working without permanent water supply.
Planets/"Scenarios"
You are crash-landing on different planets with different challenges and possibilities. I'm using descriptive names for each planet."Terra 2": earthlike planet, trees and lakes, edible fish => classic. Maybe additionally some food plants to regrow.
"Dagobah": swamp planet, hard to build something, many trees and water holes, hardly food plants, dirty water, perhaps gas eruptions (air supply) and explosions, fast growing vines
"Eden": looking like paradise, but is deadly poisonous. Perhaps a mushroom or giant flower forest with noxious spore clouds and mushroom "porcupines". The atmosphere and water could be filtered. The mycelium/rhizome grows and damages structures, "loves" pollution.
"Arrakis": sand desert world. You only gain water from condensers and it's much too precious to be wasted for power plants. Maybe introducing special turbines that are re-gaining the water from steam. No wood or fish, deadly hot during the day, deadly cold before sunrise. Sandstorms blind you and disable your solar panels. Desert-typical monsters like arthropodes or snakes.
"Atlantis": water world. No air, not much sunlight, cold, guns and flamethrowers don't work => harpoons. Perhaps building a floating base above, switching between floating and ground base.
"Mars": like "Arrakis" but without (much) atmosphere and very cold. Water is gained from ice deposits. Sandstorms, solar storms and meteorite showers.
"Hoth": ice world, deadly cold during night, weak sunlight, low oxygen. Resources are hidden below a thick ice layer, machines require extra power to function.
"Mercury": like "Mars" but deadly hot during day with harmful radiation. Because there's never been life or atmosphere, there are also no oil or other deposits beside meteorites. Metals, gas, air, sulphur, water, stone and so on are gained from regolith - the dust that lies on the whole surface. But the yield is lousy except for stone. Gas must be turned into the denser oils with a special process. Solar storms and meteorite showers, perhaps crystal-rock-monsters with laser-beam eyes.
"Venus": a hell planet. Extremly hot, day and night, acid atmosphere, rather dark even during day. Like "Mercury" but even hotter. No solar storms or meteorite showers, but all structures are constantly getting damaged (draining repair packs). "Venus"quakes, crevices and lava streams are destroying buildings. Maybe lava-monsters, extreme slow, but hard to kill.
