thanks for the disclosure :) , i think joystick movement being inaccurate depends greatly on the player , more on the player than the code , just like when you do combos in fighting games a quick diagonal often gets pushed a bit too far or not far enough, if you got the space left you can add it as an option i suppose. You can have the two key combos you have now, + wasd + cursor keys + joystick in the same game or compile separate carts then everyone gets their way heheh but you should do what you feel first imho, not "what they want", thats where the better games come from (like caves of Qud here - i dont think they even have diagonal its been a while)
nice piece of work !!!