Platform Moon was a highly unsatisfying movie. We see a group of men living in extremely claustrophobic conditions. We don't know where they are. The only dialogue during the 25 minute movie takes place between these men and a disembodied voice that responds to their commands to turn things on of off, or to open or close hatches. The men move slowly and deliberately through various hatches and narrow tunnels. Finally, we see one man get in a diving suit, and exit to the water where he begins to hammer. The movie ends.
Only during the Q&A with the filmaker do we discover that the men are in a small bathyscopic container for 30 days at a time, so that they can do repair work on a oil rig. His intention was to leave us in the dark.
I like documentaries because I learn things. Not sure I'd categorized this as a documentary.