Orcs Must Die! 2 is designed to be run with a genuine Xbox controller. If your controller is not genuine, you may want to consider emulation software that simulates an Xbox controller.
Other USB devices may be detected as controllers. Typically these are other gaming mice, Xbox controllers, steering wheels, joysticks, etc. However, we have had reports of other devices being picked up as controllers as well. Please unplug any other USB devices and then completely restart the game. (Afterwards you can try plugging them back in one by one to see which one is causing the conflict.)