ScummVM requires a little bit of extra work to launch games from a frontend. The ROM directory should, for each game, contain .scummvm file used by ARC Browser as well as a directory with the actual game files. The directory needs to be named with the game's "ScummVM name". The .scummvm file should be named the actual game name, to make scraping easier. It should be a simple text file with one single line matching the name of the game directory.

You also have to start each game at least once from within RetroArch before you can start it from ARC Browser.
Let's assume you have two ScummVM games: Beneath a Steel Sky and Day of the Tentacle. The ROM directory should then contain these items:
  • sky - Directory containing the Beneath a Steel Sky game files
  • tentacle - Directory containing the Day of the Tentacle game files
  • Beneath a Steel Sky.scummvm - Text file with nothing but the word sky on a single line
  • Day of the Tentacle.scummvm - Text file with nothing but the word tentacle on a single line