Many issues can be resolved by simply restarting your computer and verifying the game files, so please start by doing this.
To verify the game files on Steam:
Various issues can also be resolved by installing any pending updates for your operating system (including optional updates), and updating your graphics card drivers directly from the manufacturer as Windows Update can sometimes install unstable drivers.
However, if you notice that an issue occurred after a system or a driver update, rolling back the update can help instead.
Sometimes third-party applications can interfere with the game’s functionality. To exclude those as a possible cause for issues, close or even uninstall any unofficial mods and mod loaders, shader / post-processing injectors like reShade or trainers and software like CheatEngine.
Try running Steam in Admin mode. To do this in Windows, exit Steam if it's already running, find the Steam .exe file in the Steam installation location, right-click on it, and select 'Run as Administrator.
Disconnect any non-essential USB or Bluetooth devices plugged into your PC.
On some setups Windows Defender features like Controlled folder access or Smart App Control may prevent over the hill from running or block its access to the default save location in Documents.
If this happens to you, in the notification sidebar on the right you should see a prompt asking you to allow over the hill to run or access Documents. After unblocking over the hill, please restart the game so that it can create its save data correctly.
You can also add the Windows Defender exclusion manually by doing the following: