A rich world: I won't reprise all the available Rich World Techniques (Chapter 2.18) that could be used in this game, but here are a few:
 This example exists simply to demonstrate various ways of creating a rich world, including complexity and detail. Remember that it's optimal if these details have value in gameplay.
When you're running missions for the government, you learn their customs. The soldiers pay homage to the sun every morning, the discovery having been made in the year 2056 that there is a spiritual force living inside of every star in the universe, helping animate them. The spiritual forces aren't gods, but they can be communicated with and, if they're happy, they can, to some degree, help control the weather on Earth.
The spirits in suns have symbiotic relationships with planets. Planets need suns to nourish their life forms. But as the life forms evolve, the spirits in the suns are nourished from the life energy of plants and animals, as well as the more evolved emotions of higher life forms.
Information about how a star or sun thinks and feels a way of thinking and feeling quite alien to a human will become critical in solving the mysteries around you. Stars and suns think in terms of pictures and symbols, which conjure up feelings (happiness, sadness, and so on) and ideas (truth, bravery, betrayal, and the like).
You must learn this new way of thinking learn to interpret images and symbols to figure out what's going on in the world and which of the three groups are telling you the truth. After all, the sun was here long before the birth of the Earth, and knows its entire history. The sun holds the secret answer to the riddles as to whether you're in the present or the past, among other things.
This civilization has mastered space travel. One of the missions will take you inside the sun, which is nothing like what you'd expect. You'll enter right into the sun's memories.