Here is the fix
If you want the Mooncrash desktop icon too, remove the first semicolons ( ; ) before the two lines
Code:
;Name: "{commondesktop}\PREY Mooncrash"; Filename: "{app}\Whiplash\Binaries\Danielle\x64\Release\Prey.exe"; Tasks: desktopicon
;Name: "{group}\PREY Mooncrash"; Filename: "{app}\Whiplash\Binaries\Danielle\x64\Release\Prey.exe"