I saw a pre-release version this afternoon
I happened to be in Harwich in Essex today, where there is a lovely 1911 cinema. It was open as we passed and we were asked if we wanted to see a preview in return for filling in a response form. We were happy to join the 30 or so others already inside.
I won't say too much as this wasn't the final product (some sound, colour-mixing and in particular CGI had yet to be added) and pretty much anything I say at the moment would be a spoiler, but although I don't know this first film I thought this was pretty good. Tense, well paced and well acted - and I can confirm that Gumbo is definitely in the film!