The game doesn't seem to be seeing my Xbox 360 wired controller at all. The controller works fine in other games, and I don't have any third-party controller apps/drivers installed. I've tried switching USB ports, but it didn't make a difference.

Help!

I'm on Windows 10 64-bit.

Controller displays as player 1, changed ports while the game was running, changed back, quit game, changed ports again, rebooted, made sure Xbox 360 controller is controller 1 in the 'which controller to use with old games' control panel. Still nothin'.

More info! No matter what I do, I can't get the game to respond to the Xbox 360 controller.

However, it's apparently reading my Roccat Tyon mouse as a gamepad. It has one analog axis (mapped as left stick Y axis) , and when I flip the thumb-paddle the game moves up and down in the menu.

So it's reading SOMETHING as a gamepad, just... the wrong thing.

--

Update: Disabled my mouse's advanced features in Device Manager, and the game DOES pick up the Xbox controller. This is way less than ideal, since I do use the fancy stuff on it for other games (I mean, why else have one?) but it's a workaround for now.

Any idea how to make it pick up the right controller?

Just out-of-curiosity, did you make sure your controller is set as the "preferred device" in Windows?
Some games sometimes won't fully recognize a controller if it was not set that way on Windows, even though the same controller in the same system can be used without issues in most games.

To know how to do that, check "Method 3" in this page:
https://support.microsoft.com/en-us/kb/831361

If you can't find that under Windows 10, follow this other guide until you see the screenshot with the window that has the buttons "Advanced..." and "Properties", next to each other (screenshot #6). Click on "Advanced...":
http://www.howtogeek.com/241421/how-to-calibrate-your-gaming-controller-in-windows-10/

Under device manager, remove drivers, then add manually by selecting xbox 360 controller from device list. I don't remember the exact menus but that was how I fixed my wireless 360 controller
simply follow this guide here - http://driverrestore.com/xbox-360-controller-drivers-for-windows-10/

The Xbox controller driver was fine.

The problem was that the game will absolutely positively only work with the controller with the lowest driver ID. My mouse has a thumb paddle that registers as a controller.

The only fix is to disable the controller function of my mouse. There is no way to change the controller order. I've hit the same problem in a couple other games on the same engine.

It's really freakin' annoying.

Changing the 'preferred device' doesn't matter. It's strictly by what hardware is enumerated first.