The Devil-Doll (1936) review

Scientist Marcel (Henry B. Walthall), who discovered how to "shrink" humans (and animals) to 1/6 their size, and financier Paul Lavond (Lionel Barrymore), who was falsely accused of robbing his own bank (and killing a night watchman) escape from prison - Marcel kicks it early, so Paul uses his technology to get revenge against the three former co-workers who framed him.  The effects aren't too bad (considering the time it came out) and having Barrymore dress up like an older lady (complete with pre-Mrs. Doubtfire voice) using "tiny people" to steal jewels and kill shouldn't work, but surprisingly the entire movie is a clever and unorthodox gem.  It turns out all Lavond wanted to do was prove to his long-lost daughter Lorraine (Maureen O'Sullivan) - who understandably detests him - he's not some savage: their final conversation on the roof is considerably more poignant than you'd expect from a film with a demonic title.