South Park: The Fractured but Whole is taking part in what could be seen as social commentary, by making the game harder if you play a character with a darker skin.
The way South Park: The Fractured but Whole does this is that it changes the colour of your character's skin to be darker the higher the difficulty option you choose. The easier the difficulty, the lighter his/her skin tone will get.
This interesting tidbit was revealed by Eurogamer, who played a recent build of the game. According to the preview, the difficulty you choose also affects the amount of money you get.
More importantly, seeing as its tied to the colour of the character's skin, other NPCs will speak to you differently based on that choice. Eric Cartman even comments saying, "Don't worry, this doesn't affect combat. Just every other aspect of your whole life."
You're also able to select a character's gender, including male, female, and "other." You can see it for yourself in the video above. Skip to five minutes and 40 seconds for the skin colour bit.
South Park: The Fractured But Whole is out October 17 on PC, PS4, and Xbox One.