To activate DirectX 11 mode:
1. Right-click on Feline.exe in your Project Feline installation and click Create shortcut
2. Right-click on the new Feline.exe - Shortcut and click Properties
3. In the shortcut's Target: property, append the following line to the end of the directory (with spaces): " -d3d11". Your shortcut Target should now look like this:
"[Your directory]\Feline.exe" -d3d11
4. Execute the shortcut for DirectX 11 mode