I am not exactly a connoisseur of Karloff, but this film makes me want to find out more about the great master--his performance in this was truly endearing, not to mention gripping.
Furthermore, this movie should be be required viewing for modern film-makers, because it really is a masterpiece of succinctness. Not a single frame of film is wasted! The movie only lasts for 62 minutes (although I'm sure the version I saw, early one morning, lasted a good ten minutes less than that!) and yet it crams more plot into that small timescale than a great many drawn-out 3 hour epics! And yet, the real genius of the work is that it does not for a single moment seem *rushed*. Everything flows smoothly right up to the final curtain, and you are left with the feeling of having watched a "full-length" feature--a truly astonishing achievement! I glanced at my watch at about the halfway stage , not out of impatience, but out of sheer wonder at how on earth everything was going to be wrapped up to a neat conclusion within only 25 minutes or so!
This film, more than any other that I can recall, bridges the gap between the frenetic single-reeler comedies of the 20s (which crammed a hell of a lot in, at the expense of a more welcome relaxed pace), and the modern day feature. If there really was five full minutes of piano-playing in this, I can't say that it perturbed me in any way whatsoever--it merely helped to set the melancholy mood of the piece. And that five minutes of a one hour film can be dedicated solely to mood setting, without generating any feeling of slow-down, is something really quite remarkable.
A great genius *can* make a 4 hour film work... but such directors are *extremely* few and far between (e.g. Kurosawa, von Stroheim). All others should learn from the director of this work: the Occam's Razor of feature films.