Unusually for a 1930s English quota quickie comedy, this is actually not bad - in fact, it's pretty good. If you didn't know better, you'd think this was made by a big studio - although they'd probably have Fred and Ginger in it - it does have a Fred and Ginger feel to it.
You can tell this is made by a director with potential, not just because of the well composed framing but also by the way that the acting isn't just confined to those doing the speaking at centre stage. Unlike what you find in many 1930s films, the supporting cast don't just stand around like statues but react and contribute to the action. What you're seeing has a sense of reality which benefits a character driven comedy like this making it more engaging.
Considering this all happens in sixty minutes, the characters are exceptionally well rounded and believable. Judy Gunn's performance is exceptional for a little low budget movie like this - presumably helped by Powell. Her character transformation, the way she expresses her frustrations, her hidden desires and how she handles her betrayal is masterfully done. With a decent director, she really was quite a talented actress - and a very pretty one too.
Louis Hayward is the romantic lead but his character isn't the usual goody two shoes, there's real depth and personality there. David Hutcheson is the arch-villain but he to is no pantomime, moustache twiddling Dick Dastardy type which in a lesser film, he would have been. The board of directors, lounging in their ivory tower are also genuinely funny and Google Withers is a brilliant sassy secretary. You don't expect such intelligently moulded characters in a silly to-com like this - this is vastly more superior than your usual quota quickie.
Surprisingly for the time, it pokes fun at sexism in the workplace. Not quite MADE IN DAGENHAM but still good fun. Furthermore unlike in the American 1933 picture, FEMALE, a woman becomes the boss without seeing 'the error of her ways' and professing like Ruth Chatterton did that "I'm only a woman, I have no right to be a boss and I should be at home making babies." Judy's appointment is the basis of the story, it causes upheaval of course (it is the 1930s!) but the moral here is that she can be a woman and have a career.
It's ironic that the work this fictional laboratory is engaged in is making celluloid film fireproof since it was made at Fox's Wembley studio which burned down a few years earlier when the celluloid film caught fire.