What The Fog has a maximum FPS of 60 by default, (classic bhvr) and therefore must be unlocked by editing a config file.

Following this guide will allow you to set a configuration which in turn will allow you to set an FPS limit of your choice, or even uncap it entirely.

• Copy & Paste the location below into file explorer:

---

• Open GameUserSettings.ini with a text editing software (for ex. Notepad++)
  
• Scroll down until you find FrameRateLimit (around line 50)

• Modify the value to your liking, for ex. 144.000000 or 0.000000 for uncapped

---

• Right click the GameUserSettings.ini file, go to properties and check read-only
  
• Click Apply

https://store.steampowered.com/app/2139020/What_the_Fog/