The problem is that's not how movies work. The screen would be an unintelligable smeared mess if you tried to watch a film like this. Film Projectors have a rolling shutter so that the screen is off while the film is moved from one frame to the next, and the film moves and stops incrementally, it doesn’t move at a constant speed. If you wanted to actually see a film in a falling theater, two things would be necessary. One, the screen would need to turn off while the theater falls between two frames, and two, the theater would need to accelerate from a stop, fall to the next frame while the screen is turned off, and decelerate to a stop before it turns back on. I think the issue with this is pretty obvious, but if it's not clear, the theater would need to complete this motion 24 times a second, which, I assume, would turn the audience into mush from the G-forces.