The Phantom Creeps is everything an old classic B sci-fi thriller is supposed to be. It features Bela Lugosi (as Dr. Zorka), a mad megalomaniac genius with a utility belt and a sack of gadgets that would make Batman and James Bond blush, against a team of CIA-types, a reporter, and local law enforcement. Lugosi hams up a storm and really seems to enjoy himself in this immensely silly role. His somewhat untrustworthy and dull side kick, played by Jack Smith is a great foil to his overbearing stage presence, and he makes a truly great sadist! The film is replete with clever and creative (for its time) special effects (plane crashes, all sorts of random electrical currents, cloaking technology) and a lot of technobabble reminiscent of some of the less palatable Star Trek series.
For an added bonus, the creators threw in a plot, and a cast of well developed, if stereotyped, characters. This film is an edit-job of the old classic serial with the same title, and it is essentially a highlight reel - compressing all the pivot points on the winding road followed by the serial.
Ultimately, it's mindless, kinda trashy entertainment, but it's also a damn good time.