Hopefully this is allowed. This is an install script and all the necessary files to get Drastic running on Batocera on the Pi3b, Pi3b+ and Pi4. If you update/downgrade Batocera you will need to run the script again to keep things working.
This is not my own work. I found this on some french kid youtuber’s website and translated the install instructions to English. I could not find anywhere else besides this kids youtube channel that actually had Drastic running and functional on the Pi in Batocera. Enjoy.
P.S. Fair warning, Drastic works great on the Pi4 but the emulators main menu’s act pretty wonky making setup difficult. It may be easier to just edit the cfg files manually on the Pi4.