As you've both indicated, the interesting thing about this movie is its Universal-inspired Frankenstein's monster and 'devil's brood' of other familiar movie monsters. The entire plot, sadly, could have been written on the back of a postage stamp, and the musical numbers are just abominable, with the supposed 'big number' at the end of the movie, in which the monsters also feature, simply a damp squib. I think the Monster Kid Meeting was probably the ideal circumstances under which to see this; it's certainly not a movie to sit and watch alone in the hope of being entertained.