I have a large but incomplete self-made universe. Got all kinds of alien races and factions and religions and their technology. There are only a few confirmed planets other than our solar system, but all the creativity I can spare from designing alien races goes into the struggles of human colony life.

For example, the Saturn Stations are slum colonies where smuggling and murder rates are high. And while the Uranus Stations are the richer and higher class colonies, they are home to notorious human trafficking and organ market operations. Both planets, however, feature a high rate of canabalism.

As far as aliens, there are about 15. One race has a coming-of-age ritual where armor is grafted into their flesh, another race is made up of bio-synthetic beings who live in an artificial solar system(kinda like the Cybertronians in Transformers, only these beings aren't giant transformers), and another race has amazing psionic abilities.

There's more to it, but I think you get the point.