Here’s a concise review of Frankenstein Conquers the World (1965), based on the print and media materials available via the (archive.org).
"Frankenstein Conquers the World" is a 1965/1966 Toho kaiju film (localized titles and dates vary) that mashes classic Frankenstein lore with giant-monster cinema. If you found it on Internet Archive, expect a pulpy, campy creature feature rather than faithful Shelley adaptation.
: A 48-page digitized book or comic related to the broader "conquerors" or sci-fi themes of the era. Historical Encyclopedia Entries World Film Encyclopedia