Hello .PinkLightning., if you do not wish to download a program to see your computer's specs, you can also check them out through the DirectX Diagnostic Tool if you use Windows. Go to Start (lower left button of your desktop), search "Run," and enter "dxdiag" when prompted. A program will automatically startup with a list showing your computer's GPU, RAM, and other valuable information that can help us solve your problem. You should also be able to view your computer's basic specs by visiting the Control Panel and visiting the "System" section. Try if you can do both methods because I do not believe GPU is listed in the control panel. If possible, please post a screenshot or list the details of your computer's hardware listed, specifically the RAM, CPU/processor, and the GPU/graphics card.
Besides that, do you ever have any display issues (flashing screen, etc.)? You said you do not have lag issues in other games---so I am curious to know how Feralheart lags for you. Does it skip frames, or is it generally just slow? Is there a serious delay between you pressing a button/key to perform an action and actually performing said action?