Iron Lung review: Marc Fishback’s claustrophobic sci-fi horror thrives on fear
Set after a cosmic disaster, Iron Lung follows a lone prisoner sent to explore the Blood Ocean. Directed by Marc Fishback, the film is based on the indie horror game by David Szymanski.

Release date: March 13, 2026
the scariest thing about iron lung It’s not what you see, it’s what you can’t see. For most of its runtime, Mark Fishbach’s claustrophobic sci-fi horror keeps you trapped inside a rusting submarine with no room to breathe.
The film closes the hatch at the beginning and almost never opens it again. What is lying outside? A vast ocean of blood on a distant moon. What’s inside? One man, a failed ship, and the feeling that something might be going on in that ocean.
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Based on the indie horror game by David Szymanski, iron lung It marks the filmmaking debut of the YouTuber, also known as MarkLeaper, who writes, directs, and stars in the film. And to his credit, he doesn’t try to turn it into a loud, jump-scare-filled horror spectacle. Instead, he leans fully into scares: slow, creeping, and unsettling.
The situation is absolutely serious; The universe is basically dead. After a mysterious cosmic disaster called Quiet Rapture, every star and habitable planet has disappeared. Humanity survives in scattered locations in space, clinging to whatever resources are left. Fishback plays Simon, a convicted criminal who is essentially sent on a suicide mission. Their job: pilot a crude submersible called the Iron Lung through a sea of blood discovered on a distant moon and photograph whatever lies beneath the surface. Hunt? There are no windows in the submarine.
Simon navigates using coordinates and instruments, periodically firing an external camera to capture grainy photographs of the ocean floor. These images flash on the screen for a while and you’re constantly trying to understand what you’re seeing, before the film pulls you back into the suffocating interior of the submarine.
and here it is iron lung Is at its best. The film is based on atmosphere. The pipes rattle, the hull groans and the gauges flicker nervously. Every sound feels slightly wrong, and you feel like the ship itself knows it shouldn’t be here. The ocean outside also becomes more terrifying with each passing moment because the film refuses to show it clearly.
Fishback carries the film almost entirely on her own, and though the performance sometimes feels a little shallow, it works for the character. Simon does not aim to be a heroic explorer. He is a man trapped in a metal coffin, who slowly realizes that he will not make it out alive. As the mission deepens and stranger things begin to appear in those images, his increasing panic becomes the emotional foundation of the film.
There are moments when the tension works beautifully. A photo reveals something that shouldn’t be there. The submarine moves without warning. A distant figure is visible in the red water. These sequences reflect the kind of cosmic horror that relies on imagination rather than spectacle. Before you fully understand it, you start feeling fear. There is also a mysterious god-like female voice giving instructions to Simon, adding to the intrigue.
But the film also struggles with the limitations of its source material. What worked as a small, mysterious video game doesn’t always easily expand into a feature-length story. Simon spends a lot of time entering coordinates, checking instruments, and steering the submarine, and the repetition sometimes slows the pace of the film. The atmosphere remains strong, but the narrative sometimes feels like it’s wandering in the same dark waters.
Still, there’s something undeniably impressive about what Fishbach has achieved here. The film reportedly had a modest budget and was largely self-financed, yet it never feels cheap. In an era where most video game adaptations try to be big and loud, iron lung Does the opposite. It limits the story to one man in a room and lets the audience’s imagination do the rest. It may not work for audiences expecting traditional scares, but for those willing to immerse themselves in its eerie rhythms, iron lung Could be a fun weekend watch.