Betty is conduction an invention show in a tent and atmosphere that looks and sounds a lot like a circus. Bimbo and Koko, naturally, are on hand to assist. Betty and her pals do demonstrations on products like a spot remover, a cigarette snuffer and an egg cooking device. Most of this was only mildly diverting, but it was pretty funny when the sewing machine ran amok.
Unfortunately, Mae Questel (the voice of Betty) ends up singing and while it's somewhat catchy, her high-pitched voice is,...um...hard on the ears. As usual, the film features pretty good Fleischer animation and Betty--a character whose appeal I have really never understood--but to each his own.
UPDATE: Since writing this review, I have recently watched quite a few Boop cartoons. Many are pretty dull affairs--with too much singing and too little in the way of plot. However, this is not always the case and some of them were pretty charming. I still wouldn't place "Betty Boop's Crazy Inventions" among her better shorts, however.