On an Xbox controller playing via the browser under Chrome on Windows, the “south” and “east” fire buttons are exchanged relative to in-game prompts. But my inputs are shuffled totally differently relative to this Picotron Gamepad Tester thing, which doesn’t agree with either layout! Bizarre. Not sure if it’s something weird about my setup, Picotron being a moving target across its revisions, or what’s going on here…
Engine is a good start, although “jump” on dpad up doesn’t feel great on a controller. (It’s fine on a keyboard.) Best of luck developing this further if you choose to do so!