This is a Spanish film dubbed by Netflix for world-wide play on their service. I had it recommended to me by a Swede. Some people have compared it to Waiting for Godot and other Beckett works. It's certainly heavy (and heavy-handed). If you interpret it as a parable of modern capitalism, you can find a message here, but the parable is a bit flawed.
The general set up is there is a vertical hole-in-the-ground prison. One cell per level, two people per cell, very little in the way of rules enforced. Saving food is the only thing we ever see punished. And food is a problem. Once a day a platform (the one of the title) is lowered through the prison for people to eat at for two minutes, then it is on to the next floor. When the film starts, a new prisoner has just started on level 48. The platform is a complete mess, and he is surprised his roommate can eat at it. Level 48, his roommate explains, is so much better than the deeper levels.
Not much about this prison arrangement makes much sense. It becomes clear that between the monthly floor assignment resuffles a lot of people die from hunger, murder, and suicide thus freeing up space for newer prisoners. Nothing about this experience will make anyone better negating all benefits of this over a fast execution. The food prepared is lavish at Level 0 and nothing but broken plates by Level 100 or so. It does not look like enough food for the 250 levels the main character guesses the place has. Why go to all that trouble preparing it?
That said it does leave an impression.
Four snails out of a plate of twelve.