This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / Black & White
Tropes associated with the video game:
Earworm: Deeeaaaatthhh...... Oh, and also the Pied Piper arc. If you fail, the creche becomes empty and the population drops!
A fair amount of Nemesis'/Lethys' actions could count as this (from a villager's perpective, at least):
Nemesis' 'revenge' on the first/fourth land. Turning the sky red? A little unnerving, but not too bad in hindsight. A permanent storm system over the site of your old village, complete with huge pillars of lightning? Again, given that nothing is explicitly in the way of this, it isn't that bad. Fireballs raining from the sky, though... Not to mention the fate of the one village that refused to bow to him: Rather than simply killing the inhabitants, he performs a 'miracle' that sucks them under the ground and turns them to walking skeletons. Granted, it is only a game and the problem is quite easy to rectify, but still. There's also the ogre attacks on your eventual village, Nemesis' kidnapping of a man's wife to ensure his loyalty, and the fact that the land has actually has huge scars that run across it. It's not surprising that the first native you come across in the fourth land sounds utterly terrified of your presence, given that it was technically your fault that Nemesis arrived.
The initial attack on your village at the end of the first land. Picture the scene. It's a beautiful day in the norse town, and everything is peaceful as a benevolent sheep/bear/lion takes your god to the summit of a nearby mountain for another of his lessons. Then a booming voice cuts across the sky, which simultaneously darkens and releases torrents of rain. There's a flash, the town centre is set alight, and suddenly all doesn't seem so peaceful any more. Even worse would be the fate of the villagers of a player who rushes to the second land, leaving half their town to face Nemesis' wrath despite the fact that all could have been sent through to the next land.
And imagine being thrown into the portal. In one day, your home is destroyed and you're thrown into a strange tunnel into a new land, possibly never to see anyone you love again.
Your creature doesn't have a particularly easy time in this game, either. On the third land, he is kidnapped, starved, frozen, and set alight countless times by Lethys' creature. This wouldn't be so bad, except for the fact that he is clearly conscious for the entire experience! Then there's the fifth land. This is interesting. Nemesis' curse weakens him, shrinks him, makes him more like your enemy, and makes his alignment the opposite of yours at the end of each day. Thankfully, once you capture enough of Nemesis' towns, your creature is said to be strong enough to resist the curse. However, some versions of the game had a bug whereby the curse was never lifted.
There's also the small matter of what happens to the Greek capital at the beginning of the second game. Lets put it this way: there are probably more than five hundred people in that city, even more counting the soldiers that the Aztecs had already slaughtered. You escape with fifty. And this attack includes two volcanoes. And there are still people there.
On first installing Black & White, the game asks for your name. Innocent enough, until you hear names spoken in barely audible whispers. Lionhead included a soundbank of common names, which it would match to the one given during install and randomly play during the game. The experience of hearing your name spoken in this way can be incredibly unsettling.