From a game-design standpoint the current official backstory has a couple problems:
- 1) we don't know how it ends, and the one person who does has left.
2) the story is utterly disconnected from gameplay, it doesn't "set the stage" for play.
3) it centers around "the Orions" which makes it seem derivative no matter how much else is original
Some ideas have been adapted from Drek's expansion of the backstory, which had some similar motivations.
Instead of the Orions & Antarans there seem to be several ancient highly advanced races/civilizations that once inhabited the galaxy. These "Precursors" possessed the ability to travel between galaxies, and seem to have simply left the gameplay galaxy.
Each game is understood to happen in one of the untold number of galaxies effected by the Precursors, thus each game can be different, but belong to the same reality. Thus the general content descriptions can work for a wide variety of campaigns. Various different campaign stories could be built on this foundation, for instance perhaps some unfriendly Precursors are coming back, or the Upstarts could fight to summon their favorite precursor civ, or help one against another. Which of these is the case could be determined by random chance unbeknownst to the player, so that, for instance they wouldn't know if there is going to be an artifact corresponding to the Orion planet in a particular game or not.
All the playing species were all placed in this galaxy about the same time as a non-technical but sentient species. Some may have a mythical/legendary account of this while other's may believe they lived on their home planet forever. As the game unfolds the players may uncover clues that they were purposefully placed here, and the reasons for doing so (not necessarily the same in every game/galaxy), and to the identity of some of the Precursors.
How the Game Starts:
The game opens when a "monolith" falls the the surface of all the playing species' homeworlds. When deciphered, it provides the secret to Star-lane travel, something so mathematically arcane, that they otherwise could not expect to discover it for millennia. The Monolith provides no information on the identity or intentions of the monolith-builder, but comments that other monoliths are falling on other worlds in this galaxy.
Thus it is plausible that all the player species would start the game at approximately the same tech level at the same time.
But the commonality between all games is that all the Precursors seem to be gone, and they left a lot of stuff. There's no better way to enhance the exploration X of the game than including lots of useful, interesting, and unique stuff for the player to find.
Basically the galaxy is riddled with the leftovers of absent civilizations far in advance of the starting player species. The starlane system itself is believed to have been constructed by some of them. Also there are:
- Archives revealing tech,
Stasis-chambers: containing monsters, useful units, or even lesser species
Mothballed ships (sometimes superior to what the player can build,
abandoned colonies (some with advanced buildings, or still active defensive weapons),
Gaian planets, (of various kinds),
Planets ruined by lingering late-game weapons.
Stockpiles of various resources,
Planets with useful "native" Indigene species
And perhaps clues to the identity of some of the Precursors and/or their plans for this galaxy (if any)