@dewiele said in Game and Watch ‘Game B’ button mapping:

I tried MAME standalone originally and got the game and watch ROMs running however by default the TAB menu was inaccessible as the PSPi controller mappings were not set up.

You should use a keyboard first.
I you somehow use the standard runcommand :
mame = "/opt/retropie/emulators/mame/mame %BASENAME%"
and it still doesn't work with the keyboard then you could try to add "-ui_active" to the runcommand.

@jimmyfromthebay

Due to this thread I found that there was a mistake in my script and I fixed it.
So now it can create lr-mess overlays for gnw from the mame artwork.
2022-03-02-183543_800x600_scrot_resized.png
I think it's not what you are looking for, though.
It is still an overlay and transparency is always used and not perfect.

I have tried the combination lr-mess with mame artwork but never had any result,
because then the game just won't load.

Perhaps you both can find a way.
It would really be nice if it could work like you want to.