Joystick/gamepad handling needs to be redone
Aside from previously reported issues like #407 and #620, the way joysticks/gamepads are handled right now seems to cause issues with later versions of SDL.
While upgrading to SDL 2.0.20 seems to improve gamepad recognition...
...it also breaks the new default controls. The axis handling somehow gets worse than it already is, requiring the player to move the right stick up/down to rotate the camera left/right, and changing the axis settings doesn't seem to resolve the problem. (It also seems to break the rumble functionality introduced in !1695 (closed).)
!1695 (closed) is definitely a step in the right direction, but there's more work to be done after that's merged. Switching from SDL's Joystick API to its GameController API is probably the way forward.