Update (new patch 1.9.2): I've gotten some good feedback, and I've figured out why the d-pad doesn't work on some (most?) controllers. It's... a clumsy mistake on my part. Literally two lines of code was all it took to fix it. Whoops.

To explain, there are three types of gamepad functions in GM8: Buttons, axes (joysticks) and povs (d-pad). The axes and povs are hardcoded to movement and navigation, and somehow I forgot to add pov functionality to up/ down movement.

Patch 1.9.2 fixes that, adds the option to disable built-in gamepad support (incase you want to use external remapping software) and improves viewport scaling functionality.