Okay.
Go to you C drive and make a new file called "FeralHeart+" and extract everything into there. After everything is moved, go into the "Feralheart+" folder and double click "Fearalheart+.exe" and it should run. Do not move "Feralheart+.exe" out of the "Feralheart+" or it will no longer work.
If it doesn't run, re-download it. There should NOT be an installer.