Iron Lung Review

Until a few weeks ago, I’d never heard of the video game Iron Lung. Neither had I heard of the YouTube channel Markiplier, much less Mark Fischbach, whose name it bears. His feature film debut (which he wrote, directed, edited, and starred in) only came to my attention as it gained press for its impressive distribution accomplishment: with no distribution company, no marketing, and no supportive infrastructure to speak of, it opened this weekend on over 3,000 screens in the US, and over 4,100 worldwide. That’s wider than almost every 2026 release to date, including the year’s top grosser, Primate. It’s more than A24’s biggest movie Stateside, Marty Supreme. For a small genre flick made on a shoestring budget by a guy whose prior releases were direct to a free online platform, it’s nuts. It speaks to the power of amassing a dedicated following, as he and his team encouraged fans to call their local theaters to add screenings, which incepted film bookers with the fear of missing the coming wave. That attendance at Thursday evening showtimes frequently rivaled weekend crowds validated their action.

Even knowing nothing about the source material, its video game roots show almost immediately. There’s a long, winding voice-over describing the state in which humanity finds itself, a distant future in which the stars begin to wink out, and the Universe is dying in the wake of “The Quiet Rapture”. Our protagonist, first known only as “convict”, and later, Simon (Fischbach), is given a the vague mission to map the seabed and no instructions on operating his janky submersible. He’s quickly lowered into the depths, at which point he loses comms, and is left to figure things out by trail and error. There’s a wall-mounted oxygen meter with only enough precision to increase the tension, a message from a previous operator revealed by crossing some wires, and a steady flow of minor tasks he must complete to move the plot along. Oh, did I mention the sea is entirely blood?

With this premise, Fischbach is taking a huge bet on his own ability to carry a film. It’s understandable given his YouTube career and prior work. That said, being the only on screen presence for almost the entire film requires a different set of skills than simply being a lead. His performance isn’t bad, just very mixed. Mostly, he’s solid, carrying out the changes in emotional register quite well, especially wearing tired exasperation nicely. But he never quite dials in to how to be angry, either failing to sell the authenticity of the emotion, or else taking it so over the top as to be cheesy.

As a survival horror game movie in a sci-fi setting, it’s only fitting that Simon’s experience of the world outside his ship is indirect. He really only has an X-ray camera, whose screen displays haunting, gray-blue images moments after he presses the shutter. Just as he cannot be sure if the voices or shadows or tremors are tricks of his mind due to the extreme pressure (literal and figurative), the view it provides is often ambiguous. What moved that skeleton? What is that skeleton? Why is his surface contact, Ava (Caroline Rose Kaplan), so excited that he found SM-8? Why is it so damn hot? Whose radio signal did he pick up, and why does she (Elsie Lovelock) keep saying something about a light and meeting up and insisting that all will be okay? What exactly happened at Filament Station? What is this “Eden” they keep mentioning? Is it connected to “the last tree”? And most importantly, why are the researchers convinced all of this is tied up with The Quiet Rapture?

Iron Lung is laser focused on creating atmosphere, relegating these plot and worldbuilding details to the background. They’re simply devices to move the story forward, to give Simon new opportunities to lose his grip on reality. So we rarely get satisfying answers. The best we can expect are hints, mostly focused on the “what” instead of the “why” or what it all means. That could work if there wasn’t so much of it. From the opening info dump to every new piece of information Simon gathers, most of its one hundred twenty-seven minute runtime (yes, it’s over two hours long) is focused on constructing a world that begs so many questions. As it becomes clear that Fischbach intends to leave them all dangling, it gets harder and harder to care, and your engagement level drops.

It doesn’t help that it’s often difficult to make out what’s happening on screen. Given the setting, the low light levels throughout the tiny vessel are unsurprising. Fischbach does a good job of using other lighting sources to create mood, such as when Simon tapes down the camera button to generate constant pulses of its eerie light. But even then, his face is commonly draped in deep shadows, and there are quite a few points where the shake of the camera or its vérité-style roaming and imprecise framing making it hard for your eye to lock on to anything. Not that there’s a lot to see; the experience is padded out by long sequences of tedious fiddling or hopeless raging or lamenting his situation, occasionally broken up by flashbacks that answer few questions while raising new ones.

Most distracting, though, are the lack of shots that are entirely, or even mostly, in focus. This is deliberate; Philip Roy constantly employs a shallow depth of field, with objects in the background (and sometimes the foreground) blurred beyond recognition. In moderation, it’s an effective tactic to emphasize Simon’s isolation and psychosis. But when nearly the whole film is shot this way, it frustrates your ability to see what the protagonist is seeing, a huge problem given his limited chances to expound upon it with another person. In a few key moments, this prevents you from becoming stirred by the same image that excites Simon, forcing you to make an educated guess about what’s going on that will never be confirmed. Additionally, it makes the whole production feel rather cheap, as it’s a well-worn (and effective) way to hide that you couldn’t afford high-quality props or sets or costumes. Which is too bad, as the effects (both practical and digital) and sets and structures look pretty good when we’re allowed to take a peak.

While the sound plays a great role in constructing the vibe, its mismanagement contributes to the narrative confusion. In a late, extended sequence, numerous voices come through the intercom (or are they in his head?), making for a din that your mind wants to decipher, but cannot. Bits and pieces rise above occasionally, referencing previously established lore, but nothing coherent. The deployment of Andrew Hulshult’s score is comparable. While it sounds like you’d expect given the visual style and genre, it’s got a handful of unique flourishes to keep things fresh. However, Fischbach’s decision that there should never be a moment of silence, at most dropping the score to a steady, background drone, is exhausting.

Despite my reservations, what Fischbach has accomplished is admirable. Not only the distribution success, which is it’s own achievement, but the film itself. The man has been working for fifteen years, both building an audience and pursuing more and more ambitious projects. My understanding is he has no formal training in movie making, just experimentation and collaborating with other creators. The fruits of that labor are apparent. Through its flaws shines the soul of a talented, driven, resourceful filmmaker, with a demonstrated ability to iterate on his experiences. I look forward to the next time he steps away from YouTube to once again grace the big screen.