What Has (Video Game) Man Wrought?

So I was playing Xenoblade, right? And I'm at the point of the game where I've met the customary haughty advanced civilization of duders with wings on their heads. Since getting to this big silvery future JRPG city, I've been bombarded with assholes telling me how effective their anti-badguy defenses are, and how they've existed for blah blah years before us dirty humans blah blah blah. Curiously, all the side-quests I've received have been stamped with the "temporary" icon, suggesting that I should do them sooner rather than later.

Because Xenoblade is currently being about as subtle as a Buster Sword to the chops, I've decided to talk about some other ancient and/or advanced civilizations that came a cropper for one reason or another. Spoiler: That reason would be hubris, with the "another" reason also being hubris.

List items