What's next? Addressing the lack of focus on the important elements of a survival game. For example, being able to die. In the early game there are 3 big threats to survival ; Lack of shelter, lack of water and lack of food.
The most critical factor is shelter. Humans can survive several days without water and a week without food, but extremes of temperature can kill you in hours. Staying cool in the heat and warm and dry in the cold will be vitally important if you expect to survive.
The easiest way to shelter from the elements will be to find a natural cave or a ruined building. In some cases you may have to clear out its existing inhabitants first. If such a shelter is not available, the player may have to construct something.
The simplest structures the player can build will be little more than a few strategically arranged tree branches. This will stop light rain and give the player some shade from the sun, but they are fragile and will be easily destroyed by moderate winds. Since they only provide partial protection from the chilling effects of wind, a campfire will be essential for surviving the night.
Once the player gains access to better materials and tools they will be able to build more permanent structures such as huts that will also keep in warmth and provide protection from other threats such as wild animals.
Clothing will also influence your ability to stay warm. Being caught in the rain or falling into water is a nuisance when you live in suburbia and can pop home to change your clothing, but in a survival situation it can be fatal. Better find somewhere to get out of the rain and get a campfire lit before the chilling effects sap your strength.
Lack of water is the next most critical survival factor. Depending on the weather and exertion levels, humans need somewhere between 2 and 5 litres of water a day. Once the player has a shelter sorted out, finding (and maintaining) a source of fresh water will be the player's most pressing daily need.
In the early game the player may be scavenging water from whatever sources they can. If the player is lucky it will be a freely flowing river. If not, it may be a stagnant muddy pool with any number of pathogens lurking within.
Recognising if a source of water is safe to drink will be a vital skill. Contracting a water borne illness will only accelerate your dehydration and leave you vulnerable to other afflictions. The safest option will be to boil your drinking water, but this may not be possible if the player can't find a suitable container or a way to start a fire.
Food is the final factor. There is less urgency to this one, but it cannot be ignored completely. There will be many food sources available to the player depending on their skill level. In the early game it will be edible plants and less palatable options such as insects. This will only get the player so far though. If the player wants to survive long term, fishing, hunting and trapping will provide improved sources of food if the player has the necessary skills and equipment.
As with water, food borne illness will be constant threat, so avoid spoiled food and cook things prior to eating.
In reality if you're in trouble you'll probably die from a combination of these factors.
Without food you may lack the energy to build a shelter. Without shelter your hands may become numb with cold and you're unable to start a fire. Without fire you shiver through the cold night and are unable to boil your drinking water before consumption.
Your thirst has been quenched, but you're exhausted from lack of food. You're approaching the beginnings of hypothermia and you've just started having stomch cramps, nausea, vomiting and dizziness.
Sometimes life is cruel.