There were multiple sources of inspiration. The chiefest of them was Master of Orion 2 (a renowned classic in the 4X genre). The setting is an original universe of mine tailored for science fantasy/fiction with magical facets, kind of like Star Wars in some respects. The universe itself is (loosely) inspired by Spiral Knights, a Zelda-like MMO in which you play a tech-knight who crashlanded from a starship on an alien world.

You know how many space empire 4X games have an extinct Precursor civilization who left behind artifacts that other empires can discover? The Crescents are supposed to be that empire. There were no other races before them, no aliens who evolved parallel to them, no previous empires for them to build upon. They were the first, the original space empire in this galaxy. The other empires only existed because the Crescents allowed them to and nurtured their development. Their time is coming to an end, and we, the players, will be witnesses to it.