The list of animals proposed to date seems heavily weighted toward predators.
This is nice, given the perogative for gameplay and combat. But IMO the ambience of the natural environment would be enhanced by a credible ecology and food chain.
To that end, I'd suggest that there should be about 10 times more herbivore / scavenger / omnivore than predator species, and of all sizes, not necessarily just on a scale suitable to threaten humans.
I'd be particularly impressed with a species so large that humans are beneath it's notice, and the threat posed by it is purely incidental to the creature's passage through the landscape.
Another attractive scenario would be a gargantuan amphibious carnivore that occasionally forages the shores of it's aquatic home for a few extra morsels - perhaps adding some extra difficulty to defending the human settlement.
As well, similar attention to plant and other passive / immobile species would be highly regarded. Perhaps an innovation like predominantly blue or orange colored vegetation (presumably based on different organic principles than terrestrial vegetation), given the independent evolutionary history of the planet, would be plausible.
Anyway, something to think about (or not).
Crystal Core to the Max...
Well, what with the uncomfortably close parallels between the Crystal Core story and the setting for Unreal all those years ago, I thought I'd better introduce a little innovation to spice things up a bit. A heart-wrenching story with all the right ingredients - creative, yet plausible; twisted, yet true-to-life; stranger than fiction, yet down-to-earth; and all the while, in touch with the adventurous mavericks we'd all really like to be.
Firstly, the Ch'thdas encounter detectable levels of methane for the first time when they make human contact, and by a peculiar quirk of nature, this innocuous gas has the effect of sending them into hysterical fits of uncontrollable laughter, so much so that they can't even remain on their feet. Needless to say, when the human settlers have just enjoyed a traditional beer fest with lots of sauerkraut and onion burgers, any proximous Ch'thdas are apt to be in for a frolicking good time. Ironically, by virtue of their alien metabolism, the Ch'thdas give off nitrous oxide when excited - and so the human folk tend to respond to nearby Ch'thdas by a similar collapse into hysterical fits of mirth and amusement.
Thus it is that any attempt at close quarter combat between humans and Ch'thdas inevitably ends in gaiety and merriment, with humans and Ch'thdas sharing a brew and exchanging tall stories around the campfire well into the night.
A corollary of these peculiarities is that any human expedition caught in hostile Ch'thda territory has only to sustain a tolerable level of flatulence to shield themselves from abuse and make their way to safety.
Needless to say, humans and Ch'thdas quickly develop an affinity for each other, sharing their language, culture and technologies. As it happens, the two species have complementary traits which promise to amplify their combined strength and prosperity. The humans live on the surface, the Ch'thdas dwell underground. The humans have mastered agricultural methods to produce an abundance of foods on the surface, whereas the Ch'thdas are experts in mining and building technologies. And lots of other technical and anthropological details too numerous to mention. Suffice to say that an interspecies symbiosis spontaneously develops between the Ch'thdas and humans.
Meanwhile, those sniveling Lynirs smell bad to both humans and Ch'thdas - and they never seem to do anything but complain endlessly. Rumor has it that they've been planning to bring swarms of the deadliest vermin in the known Universe to the planet - litigation lawyers, credit card vendors, trauma counselors, insurance merchants and health-care professionals! If they're not stopped, the planet is doomed!
So the humans and Ch'thdas courageously unite to fight the good fight against the evil Lynirs. But they have a formidable task, seeing as how the evil Lynirs have already unleashed their genetically mutated abominations, the E-Ch'thdas, onto the global ecology.
Fortunately for our heroes, in order to accomplish their genetic engineering objectives, the Lynirs grafted various exotic plant genes (hell, they're ALL exotic - it's an alien planet, right?) into the E-Ch'thdas' DNA (or whatever it is that Ch'thdas have that can be modified). The humans accidentally discover that E-Ch'thdas are highly susceptible to Glyphosate herbicide when a crack team of SAS E-Ch'thdas are discovered dead and dying on a recently sprayed patch of bindy weeds.
With this unexpected strategic advantage, the combined might of the human-Ch'thda alliance rallies against the evil Lynirs and their marauding E-Ch'thda offspring, wiping the bastards out by the millions - the E-Ch'thdas in a touchy-feely kinda way, and the Lynirs by more traditional methods.
However, the Lynirs, cunning whingeing devils that they are, are not to be outdone. In a secret research establishment located in a place so secret even THEY don't know where it is, the Lynirs have contracted a band of renegade Monsanto scientists to whip up a new breed of Roundup Ready E-Ch'thdas! If they succeed in this desperate gambit, then once again our heroes will face a dire and uphill battle to rid the planet of these monsters.
Just to compound things further, the Japanese have finally wiped out the last vestiges of whale species back on planet Earth. Greenpeace is consequently forced to seek out a new cause to draw revenue - something worthwhile, constructive, and for the common good. Instead, they send an army of Greeny mercenaries to the alien planet to fight for Lynir land rights.
So now things are getting just a little chaotic and unpredictable. Five armies, two coalitions, pitted in deadly battle amidst all the mayhem and danger that a vibrant alien ecosystem and a bucketload of advanced weapons technology (not to mention psychotic Greenies) can provide.
But wait - there's more!
In a bitter twist of exquisite irony, all that nitrous oxide and methane being passed by our heroic allies, the human and Ch'thda settlers (especially after the weekly beer fests), destabilizes the planet's atmosphere and triggers a spiraling cycle of climatic change which alternates between increasing heat and cold. At some point, this causes sufficient loss of the planet's polar ice caps (which it apparently has) to release a horror unlike anyone (even the Lynirs) have ever seen before - the original, ORIGINAL inhabitants of the planet.
Which causes the release of a lot more methane and nitrous oxide (and whatever the Lynirs give off).
So now we have five armies, who continue to squabble amongst themselves, fight for food and rape each others' horses, but who also unite in a last-ditch battle for survival against a SIXTH army of real nasty SOB's who, amongst other wicked habits, delight in picking the wings off flies.
And what makes these last characters so scary is they are masters of the mystic arts - so they can do all sorts of arcane and spooky stuff that technology doesn't have any answer to. And they drink Diet Pepsi.
The only ones that seem to have any idea how to fight these new monsters are the Greenies - because the magic ones don't understand the minds of the Greenies (not even in an abstract, arcane sense), and they fear what they can't understand.
Well, that about does it.
Now THAT'S a game I'd like to see.
