I've rarely seen anything about the X-Com story talked about here, just game play.
Something just occurred to me.
What happens when X-com aborts a snakeman terror mission with still living cryssalids or zombies?
If cryssalids are like tribbles and "born pregnant", which seems to be the case given that a newly hatched cryssalid can infect people, wouldn't X-com aborting the mission lead to a sort of zombie apocalypse?
I just thought it was odd that those terror sites disappear if you abort, rather than remaining until you manage to complete them. Even remaining until they would normally disappear so you can bring in another transport would make more sense.
For that matter, why do the terror sites disappear? What happens to them? There is no sign of the terror ship at the attack site, and even if you assume that it returns, why can't you detect the extraction ship? If it's a stealth extraction ship, why wouldn't they use it for insertion?
So what happens? Does your failure man the governments nuke the place to stop the spread of the cryssalid plague? I use the term "nuke" loosely, it encompasses any use of weapons of mass destruction like a FAE bomb.