Your body interacts with the environment, so this counts.
Warmth - Level of body heat. Lets use 1000 as the optimum level. When you get too hot, this increases until you reach 2000. When you get too cold, this decreases until you reach 0. Various conditions based on the heat level can be "scripted".
Visual Impaired - Occasionally, when you are in a "sunny" region, you may once in a while random look up in the air and see a bird, or a sign. 15% chance that you get the "Visual Impaired" status and a medic blinds you (or you lose vision, and a small air unit gives you vision).
Screech - The ability to hear sounds correctly is very important. When the hearing level goes down, sounds fade, and become less noticable, sometimes even incorrect.
Smell - Perhaps you are walking down a path and are in search of a quest item, say a flower. In conjunction with Vision, if you cannot "smell" the flower, you may select the wrong one.
Hygine - In a town, should you not take a bath or some form of cleaning yourself, you become "dirty". Players lose a "charisma" level should they not be clean. This results in people not answering you, people starting to hate you and even those who would kill you for your smell. Hygine also works with smell, as you may smell your foul odor (or that of a nearby smelly guy).
Hunger - Those who do not eat suffer decreases in speed, increased fatigue, and chances of "whiting out" for several seconds. During this period, anything goes, wolves can eat you, people can mug you, a tree can somehow digest you.
Thirst included.
Alcohol - You drink alcohol, you're impaired. If you want to water a plant with alcohol, try it. When you are impaired, certain moves are canceled out, some work normally, and sometimes, you may just get yourself killed.
Water - Water quenches your thirst. You use it to prepare certain foods, water certain plants, and wipe off those stains on your vest. Collected in a cantina, travel via boat, make up your mind.
Trees - Trees provide cover from enemy missile fire, they allow some level of hiding, and may increase your missile fire power.
Traps - Having a location with several zerglings burrowed makes the terrain look "different". With that in mind, it could be a trap, a hidden treasure. Let the adventurer decide.
Resource Collecting - Burrow a zergling at a resource deposit, say a tree. It will forever be burrowed, and forever healed. After an allocated amount of time, a resource drop appears, and you collect it. Be logical, missile units cannot do this. Shooting a tree wont get you a log, it'll get you a branch with a million holes in it.
Fishing - Junkyard observers atop of water look like swimming fish. Casting a DWeb over them unravels a random fish which the player swoops by and captures (or kill it). To make it more reasonable, why not have a person who beats the fish down? (Tux)
Foraging - You never know when you might spot some food. A random sequence could allow you to forage food if you are near a bush or a tree.
Fear Factor - The character doesn't have nerves of steel. They aren't willing to fight giant dragons, or even tiny ants. A fear factor means that the character will try to run away from such a monster. Once they have killed enough monsters (alone or in groups), or they have witnessed a monster long enough, they may eventually lose "fear factor".
...And more, but I'm lazy. SO HA.
None.