This serial, like many serials, often feels as though it's dragging and dragging, and the multiple cliff-hangers, which are so easily dispatched with, got somewhat old quick. No doubt there was some fun to be had here, and there were some entertaining sequences, but given the length of this adventure/action serial, it's not something I'd go out of my way to recommend (Boris Karloff would be the best selling point, I'd wager).
Have you set eyes upon this serial?
(http://fight-evil.com/movies/years/1931/319-1.jpg)