Hi!
Haven't encountered this issue before, so it's a bit strange. Do you have any actual gamepads or external peripherals connected at all? Maybe something that can act as a controller? (airplane joysticks, some rare controllers, etc.)

If not, the best solution I can give off the top of my head is to delete options file from AppData\Roaming\Mondealy_Full

Another possibility is that you've encountered some rare edge case softlock spot, where character's state is set to not being able to move, in that case not keyboard nor gamepad will control your character and you'll need to go to a previous savefile.

Sorry for inconvenience