That's a good point. Since I made the game in NESMaker, it would take some work, but it's certainly possible with some modifications to the base controller code. Cheers.
Well, as a learning exercise, I wrote that SNES gamepad patch.
You can turn on a SNES gamepad in Mesen or attach a real SNES gamepad to the NES via an adapter.
I don’t know if the full game is playable this way, but I was able to do the first few minutes of it with the SNES gamepad.
https://jordigh.com/Crater%20Song%20-%20SNES%20gamepad.ips
That's awesome! I'll look into it and see about an update. :)