The demo can be downloaded for free
It claims compatibility with Windows 7 on the store page:

...but in reality calls a function that isn't in Windows 7's user32.dll:


Just using VxKex doesn't work (maybe it doesn't work for .NET apps, as it didn't say anything about kxuser, or whatever the file that has user32.dll exports is called)
However, the game is based on .NET Framework (you can easily notice this when it starts to reinstall .NET Framework 4.8 for no damn reason on first run, as well as from the mention of "CLR" in the crash dialog)
This means, that you can simply use dnSpy to remove the call to the function that doesn't exist.
dnSpy download link: https://github.com/dnSpy/dnSpy/releases
Patching steps:
1. Open "KitsuneTails.exe" in dnSpy
2. Use dnSpy's search tool (at the bottom, or the search icon in the toolbar) to search for GetDpiForSystem
3. It will show you only one thing, double click it
4. Right click anywhere, then click "Edit Class (C#)..."
5. Remove the following 3 lines:

6. Scroll down until you see the following 6 lines:

and delete them too (alternatively you can click Compile after doing step 5, it will show you an error, double click on it and it'll bring you to the relevant piece of code)
7. Click File > Save All..., then just click OK
After that, you're done.
