To configure button mapping, you have to edit the file named gngeorc in gngeo_pepone/conf and add the following line:
then, you have to suffle the A,B,C,D values as your convenience
you can also do it as a per game basis by putting this line in a file named <game>.cf in the conf directory
for example mslug.cf for metalslug
This is great information; thanks a lot.
In addition to shuffling the player 1 controls around on the keyboard, though, is it possible to map the analog stick to the directional controls (this would make it easier to perform circle motions in fighters, I think)? This sounds like a non-trivial adjustment, so I'm assuming analog-derived control isn't possible in this version, but you never know...
Also, is it possible to configure a second player in the same way as the first player? Could I add a line "p2control A=..." and have it work as expected? I'm a little more hopeful for this one being possible...