Can I play a movie (mp4) in reverse in Quicktime Player for Catalina?

Woodwose,

While you can reservse playback after reaching the end, there isn't an option to export or save files so they play in reverse. Although there isn’t a way to change this, we love hearing about things you’d like to see in future updates. You can leave feedback here: Product Feedback

Cheers! 

Howdy Woodwose, 

Thanks for reaching out in the Apple Communities. We understand that you’re wanting to know how to play a movie in reverse in QuickTime Player. We can help!

To do that, once you get to end and of the movie, press Command-Left Arrow. Keyboard shortcuts and gestures in QuickTime Player on Mac

Take care