From the rules, I would interpret that as no:
Use the same control limitations as the GameBoy (D-pad, A, B, select, start). These can be mapped any way you like.
I only made the changes as I wanted to have a go at the game and it was the only way I could get it to run with the version of LOVE I have installed. I just mentioned it in case that was something you were thinking about doing yourself so you wouldn't have to duplicate the effort. I was quite impressed that those were the only changes required if I'm honest :)
On the controls, they work fine, just pressing left control when using WASD felt a little awkward for me. I only had a quick go on my lunch yesterday and didn't manage to finish so am going to have another go today, though what I saw was very nicely made. Well done!
The exe wouldn't run on Windows 10. The error complained that MSVCR120.dll was missing. Not sure where that comes from.
I was able to get it to run on Linux by extracting the exe like a zip file and making a few code changes to make it support Love 11.x. I replaced calls to audio Source:isStopped with isPlaying (and negating the value obviously) and the call to logob.:refresh with logob:replacePixels(logoDataB) in splash.lua. I also found the controls awkward, so I changed jump to "J" and shoot to "K".
Looks absolutely gorgeous. The combat took a few goes for me to get the hang of but once you get the flow it's very satisfying. I do think being able to move to the other side of the enemy would be a simple but big improvement for the combat, my only gripe was constantly rolling to the right. Well done!