The different alien races in GCII are actualy very similar, in form and function. Now, I understand that it is so for gameplay reasons; you cant have widely different races without making balancing a complicated nightmare. Stardock did a very good job in diversifying the techtrees, the styles and personalities of the different alien species reflect different scifi tropes, and it does so very well.
But I've just finished Blindsight, by Peter Watts, a scifi novel which features a very "alien" alien. And I'd like it if we could pitch ideas at how this species would fit into the GalcivII mold. I'm also just happy to share this novel here. Its pretty drat good, and its freely available on internet (links are provided bellow).
Now for some context (and obligatory spoilers):
Peter Watts is a marine biologist, and he use his knowledge in this field, and in some other fields, to raise questions about the nature, and the importance, of consciousness. The intellectual argument of his book is that consciousness is an unecessary fluke. Long story short: aliens arrive in our solar system and begin to terraform one of our planet. So we send a ship at them to assess what is going on. The crew find out that whatever is terraforming the planet isnt conscious at all; it just "does" things, and despite their unconsciousness, the aliens are very capable. They can communicate and hold a conversation in english, without having any idea of what they're saying. Yet they are so alien that the very act of communication is an act of war.
A critic of the novel:
"The difference between a bee's honeycomb and a human's spaceship, Watts suggests, is one of degree, not kind. They are both attempts to solve a problem. Humans may be very, very complex, but they are in principle as comprehensible, and as part of the world, as anything else.
What impresses most about the book is the extent to which Watts follows through on the implications of this stance. For the characters, Blindsight's story is a lesson in abject humility. Many characters in many sf novels over the past fifteen years or so have learned that space is not a venue for human stories, but the crew of Theseus learn it more thoroughly than most. As in Bruce Sterling's "Swarm," and some of Stephen Baxter's work (such as the grand Evolution), the value of consciousness itself is questioned. Control is an illusion, after all: think about moving your arm, and your arm will already be in motion. We exist after the fact -- or, as Siri's friend Pag puts it, "We're not thinking machines, we're -- we're feeling machines that happen to think."
We are observers, not agents, and where's the survival advantage in that? Watts's aliens, certainly, think rings around his humans and posthumans. They can detect the electromagnetic fluctuations of a human brain, and rewire them in real time. They can time their movements so precisely as to hide in the saccades of our eyes. And they can do it, in part, because they are not conscious, because consciousness is expensive: "I wastes energy and processing power, self-obsesses to the point of psychosis [...] They turn your own cognition against itself. They travel between the stars. This is what intelligence can do, unhampered by self-awareness," is Sarasti's blunt assessment. We are a fluke, a mistake; in evolutionary terms, a dead end. Once we get beyond the surface of our planet we are not fit."
About the aliens themselves, from the novel;
"Imagine you're a scrambler. [nickname of the aliens]
Imagine you have intellect but no insight, agendas but no awareness. Your circuitry hums with strategies for survival and persistence, flexible, intelligent, even technological—but no other circuitry monitors it. You can think of anything, yet are conscious of nothing.
You can't imagine such a being, can you? The term being doesn't even seem to apply, in some fundamental way you can't quite put your finger on.
Try.
Imagine that you encounter a signal. It is structured, and dense with information. It meets all the criteria of an intelligent transmission. Evolution and experience offer a variety of paths to follow, branch-points in the flowcharts that handle such input. Sometimes these signals come from conspecifics who have useful information to share, whose lives you'll defend according to the rules of kin selection. Sometimes they come from competitors or predators or other inimical entities that must be avoided or destroyed; in those cases, the information may prove of significant tactical value. Some signals may even arise from entities which, while not kin, can still serve as allies or symbionts in mutually beneficial pursuits. You can derive appropriate responses for any of these eventualities, and many others.
You decode the signals, and stumble:
I had a great time. I really enjoyed him. Even if he cost twice as much as any other hooker in the dome—
To fully appreciate Kesey's Quartet—
They hate us for our freedom—
Pay attention, now—
Understand.
There are no meaningful translations for these terms. They are needlessly recursive. They contain no usable intelligence, yet they are structured intelligently; there is no chance they could have arisen by chance.
The only explanation is that something has coded nonsense in a way that poses as a useful message; only after wasting time and effort does the deception becomes apparent. The signal functions to consume the resources of a recipient for zero payoff and reduced fitness. The signal is a virus.
Viruses do not arise from kin, symbionts, or other allies.
The signal is an attack.
And it's coming from right about there.
*
"Now you get it," Sascha said.
I shook my head, trying to wrap it around that insane, impossible conclusion. "They're not even hostile." Not even capable of hostility. Just so profoundly alien that they couldn't help but treat human language itself as a form of combat.
How do you say We come in peace when the very words are an act of war?
"That's why they won't talk to us," I realized.
"Only if Jukka's right. He may not be." It was James again, still quietly resisting, still unwilling to concede a point that even her other selves had accepted. I could see why. Because if Sarasti was right, scramblers were the norm: evolution across the universe was nothing but the endless proliferation of automatic, organized complexity, a vast arid Turing machine full of self-replicating machinery forever unaware of its own existence. And we—we were the flukes and the fossils. We were the flightless birds lauding our own mastery over some remote island while serpents and carnivores washed up on our shores. Susan James could not bring herself to concede that point—because Susan James, her multiple lives built on the faith that communication resolves all conflict, would then be forced to admit the lie. If Sarasti was right, there was no hope of reconciliation."
The alien ship, Rorschach:

"And suddenly Rorschach snapped into view—no refractory composites, no profiles or simulations in false color. There it was at last, naked even to Human eyes.
Imagine a crown of thorns, twisted, dark and unreflective, grown too thickly tangled to ever rest on any human head. Put it in orbit around a failed star whose own reflected half-light does little more than throw its satellites into silhouette. Occasional bloody highlights glinted like dim embers from its twists and crannies; they only emphasized the darkness everywhere else.
Imagine an artefact that embodies the very notion of torture, something so wrenched and disfigured that even across uncounted lightyears and unimaginable differences in biology and outlook, you can't help but feel that somehow, the structure itself is in pain.
Now make it the size of a city.
It flickered as we watched. Lightning arced from recurved spines a thousand meters long. ConSensus showed us a strobe-lit hellscape, huge and dark and twisted. The composites had lied. It was not the least bit beautiful."
We never see the aliens themselves. At some point the alien ship produce these starfish-like entities, the so-called scramblers, but we understand that they're more like maintenance tools than actual creatures. What we encounter in the novel is more like a dandelion, that travels between solar systems to terraform planets, and which originated from a civilization that is probably long gone and unknowable.
If you have more questions about the novel or the aliens, I'll gladly answer them.
So there you have it. Could we have a race like that in Galciv? What would it do? A race who's only surviving relic is an intergalatic space dandelion, who's function is to populate planet and spread. But a dandelion that can communicate because it is smart enough to pick up speech patern and grammar and syntax on the fly, but not smart enough to understand the content of what is being said.
Could I base its techtree on one of the major techtree? Or should I go for something more radical? Whats if the original colony was Rorschach itself? A growing city-sized ship (that would be bound to the original planet however)?
I'm thinking of going for something that has ease at colonizing, soldiering and population growth, but difficulty in diplomacy and space militarisation.
Any ideas?
Ps - I feel like I've put way too much effort into this.