This is the most bizarre issue I've ever seen in a game:

I can change the direction Sam aims by moving the right stick.

That's it. I can't move, the left stick, triggers, and buttons do nothing. But Sam will spin around with the right stick.

Edit: Well, the game only works with the first controller in the list.

I had to disable my other controllers to push the X1 pad to the top.

This is an annoyingly common problem with indie games, and there doesn't seem to be a good solution, just workarounds.

It does, but it's slightly different!

With my Roccat Tyon enabled, my Xbox One pad's right stick and D-pad now work in the game, but the left stick and buttons still don't. Disabling my Tyon's game controller functions fixes everything.

(I wish Windows had a way to change the order of controllers, but it only does for 'legacy' software. They really need a way to do it for all software.)

I should pull out another XInput controller and see if it also causes issues. (It has in other games, but that doesn't necessarily mean it will in this one, of course.)