Update v1.3.6 adds support for a bunch of classic SNES and NES-style gamepads:
All should work on all platforms with no additional drivers.
The wireless gamepads all work via USB OR via Bluetooth, but not both at the same time, otherwise the game thinks two pads are connected and the game will show a phantom non-working pad.
Most wired SNES-style USB Gamepads should work too - tested with pads from CSL and PiHut. Be wary of the very cheap SNES-style pads, the quality is usually reflected in the price!
Please let me know if you have a gamepad that doesn't work as expected and I will add support to a future build.