Complex sentence: The game was successful enough, however, to justify several accessories and supplements announced immediately after the core book's release, namely "DataPack" (initially called "Dossier Pak"), "FlashPak", "Gangbook" and "AltCult Insider".
Split into simpler sentences: The game was successful enough, however, to justify several accessories and supplements which were announced immediately after the core book's release. This included "DataPack" (initially called "Dossier Pak"), "FlashPak", "Gangbook" and "AltCult Insider".