The comedy is simple: we see a 1963 Italian Hercules movie, with an "ad-libbed" English language soundtrack. We've seen this kind of thing done before. Many of us have seen it done better. I wouldn't be surprised if the people responsible for this very film have done better: it's based on their live performances, after all, and it would be surprising if they hadn't, on some nights, hit higher peaks than they do here. But that doesn't matter: the great thing about "Hercules Returns" is the way the frame story enlivens everything else about it.
Our three heroes have just opened an independent cinema, and an evil multiplex baron has seen to it that the only film they have to screen is cheesy, thirty years old, in Italian, without subtitles. They screen it anyway, ad-libbing all the dialogue and sound effects. Of course, the actors don't really ad-lib: they've seen the film before and they know what's coming next. But it's much more fun pretending that they're making it up as they go along than it would be to attend a performance in which they really were. Whenever they say something that turns out to match up with what happens NEXT rather than what's happened already, it's a delightful miracle - and because it really wasn't a miracle, because we knew all along that the performers were in no danger of slipping, we don't feel nervous on their behalf, so we're free to laugh. It's like watching the barn front fall on Buster Keaton, who survives because he by happy accident standing where the window landed. It's both thrilling and funny. If it really WERE a happy accident it would be neither.
The reaction shots at the start serve a similar purpose. Every few seconds, at first, we cut away from Hercules to the cinema audience, who are laughing merrily - and at first I though this was an insulting way of telling us, the real audience, that what we were watching was funny. I was wrong. The film does away with reaction shots after a couple of minutes, but they were needed early on to reassure us that the cinema audience was indeed enjoying, and would continue to enjoy, the show. Once satisfied on that point we're free to enjoy it ourselves. Not only do we laugh all the more helplessly, but every time we do, we feel more certain that the heroes are going to succeed.
