You've had gamepad selected as your primary mode - this probably happened, because you had it plugged in and activated while running the game.
Go to: [SystemiDriveLetter]:Users[YourUserName]AppDataLocalLowRobot Gentleman Studios60 SecondsSettings.dat
You can try two things:
1) Delete the file and restart the game without an attached gamepad. See if it works.
OR
2) Edit the line ControlMode=2 to ControlMode=1 in the file