Note: This is a C1 guide, but it works for C2 as well. I noticed someone asking about broken settings in the forums, so I thought I'd post it here as well.

Broken settings seems to be due to corrupted save and settings files. To generate new ones:

• Hit the Windows key and r and type appdata into the prompt that comes up. This should open your AppData folder.
• Navigate into AppData\Local and delete the folders AppData\Local\Poppy_Playtime and AppData\Local\Playtime_Prototype4. You may only have one or the other. When you relaunch the game, you should be able to change your settings. Note that some of the settings are currently broken and can not be changed at all.