Can anyone explain that feature to me and how it works?
Read the documentation:
https://recalbox.gitbook.io/documentation/v/francais/usage-basique/fonctionnalites/systemes-virtuelsAnd watch the video tutorials (enable subtitles):
https://youtu.be/ZhdgY_2_SIQ?t=1540I can create a virtual system like one for light gun games but I can create one using genres I choose, is this correct?
Yes. In fact, with that you answered your previous question yourself. ☺
When I enable that, I get some fighters but not all and I get a lot of other games.
My games are scrapped (from prior recalbox versions).
After updating the system, you need to update your gamelists, to avoid compatibility problems between the versions.
Also, for the virtual systems to work correctly, the games must have the correct tags in the gamelist: if the game is not classified under the "FIGHT" genre, it will not be added to the "FIGHT" virtual system.
I recommend using external software to update your gamelist (and/or edit manually if necessary) - it is easier. I recommend Skraper or ARRM (use whichever you prefer):
Skraper:https://www.youtube.com/watch?v=G388Gc6kkRs&list=PL2oNQ0AT7fx2ExiSNrfHUzga5GnogI4sh&index=22&ab_channel=Recalbox ARRM:
https://forum.recalbox.com/topic/11850/arrm-another-recalbox-roms-manager?_=1609592968003