Even though i'm quite late, if you have a controller attached on your pc, it most likely will use your controller for the controls also if you go back to the main menu and still have the controller attached it will change back to the controller again (at least for me) just wanted to note that tooI already tried that.
I even reinstall the game and used all the controls expect the S button.
The ←↓→ button did not work nor using the other controls work.
The only control that did anything was the S button which made a sound.