@mitu
Well...you mentioned something important..." hiscore.xml is created after I get an entry on the board".
Im using analog controls and I'm not able to input the initials as the intensity of the pedal is not strong enough to hit the inital. So...the initials left in blanks despite my score was the first in the table.
Wel...seems that, oposite to arcade version, empty initials is not a valid record....concecuentally hiscores.xml was not updated....
Changing analog controls to digital let me entered initials and the hiscore table was succesfully updated...
PROBLEM SOLVED.
THANK YOU

So I've copied the 5 zip files from mame2010

outrunb.zip outrundx.zip outruno.zip outrunra.zip outrun.zip

with just outrun.zip extracted I get the message:

cannot open rom: epr-10381a.132

managed to get all the files from all those zips and then get "illegal instruction"

ROMs are not included. Did you check the documentation for that game and install the correct ROM?

https://retropie.org.uk/docs/Cannonball/

I got the non-libretro version working for pi zero (Retroflag Gpi case) and wrote up a guide in case it helps anyone interested in Cannonball on Pi zero: https://sinisterspatula.github.io/SuperRetropieGuides/cannonball and also, if it helps retropie dev's in adding a pi zero specific version, my modified repository that worked for zero is located here: https://github.com/SinisterSpatula/cannonball

I apologize for abandoning this thread for so long... you see I had some trouble compiling it on macOS the past month and someone just recently solved the issue for me - there were NO known macOS binaries on the internet for a few months so I couldn't test it locally on my computer

Thank you all for resolving this issue now! Sadly, I can not reproduce this solution on either macOS or Windows... but that is another matter...

@BuZz - so would it be possible to push a new symlink for this into the repo?

@proxycell Thanks mate. I sent you another reply lol

Replying to myself, incase anyone else has the same problem and stumbles across this post - this was a scraping issue, for some reason the scraper is no longer retrieving the correct information for Cannonball and I needed to edit the metadata manually. (Selected 'Space Engine' in Ports menu, pressed select to bring up Emulation Station menu which allowed me to Edit the Metadata for this entry)