Iron Lung (2026) Movie Review: A Claustrophobic Descent into a Crimson Abyss of Existential Dread and Visceral Horror

Iron Lung (2026) marks a significant milestone in the evolution of digital-age creators, serving as the feature-length directorial debut of Mark Fischbach, known to millions globally as Markiplier. Produced under the banner of Markiplier Studios and distributed by Fathom Entertainment, the film is a science fiction horror hybrid that adapts the minimalist indie game of the same name. Written, directed, and starring Fischbach, the screenplay expands upon a terrifyingly unique premise: a post-apocalyptic universe where every star and habitable planet has vanished in an event known as The Quiet Rapture. The remnants of humanity, huddled on aging space stations, are forced to scout a desolate moon containing a vast ocean of liquid blood in a desperate search for resources.

The main cast features Mark Fischbach as Simon, a convict sent on a suicide mission, alongside supporting performances from Caroline Rose Kaplan as Ava, Troy Baker as David, and a surprise appearance by Seán McLoughlin as Jack. Released on January 30, 2026, the film matters not only as a high-stakes genre experiment but also as a proof of concept for independent, creator-led cinema at a blockbuster scale. It attempts to translate the singular, crushing dread of isolation into a cinematic language that is as visceral as it is visually arresting.

Story and Screenplay: The Nightmare of the Crimson Sea

The narrative structure of Iron Lung is an exercise in escalating tension within a confined space. The screenplay by Fischbach leans heavily into the lore of the Quiet Rapture, a cosmic horror concept that provides a chilling backdrop for the personal stakes of its protagonist. We follow Simon, a prisoner who is essentially a disposable asset, as he is bolted into a cramped, windowless submarine—the titular Iron Lung. The plot follows his descent into the blood ocean of an unnamed moon, guided only by a map and the voice of a supervisor.

While the premise is undeniably strong, the pacing often struggles with the weight of its 125-minute runtime. The film frequently circles back on itself, both literally and figuratively. One segment involves Simon navigating an underwater maze that feels designed to pad the narrative, leading to a sense of repetition that may frustrate viewers seeking a more traditional progression. However, this circularity reinforces the themes of futility and the grinding nature of life under an uncaring, authoritarian regime. The script's greatest strength lies in its world-building through environmental storytelling, though it leaves several significant plot questions unanswered, opting for a lingering sense of mystery rather than a neat resolution.

Acting and Characters: Performance in a Pressure Cooker

Mark Fischbach delivers a physically demanding performance as Simon. Much of the film relies on his ability to convey terror and exhaustion within the few square feet of the submarine’s cabin. Since Simon is largely alone, Fischbach uses subtle shifts in breathing and frantic eye movements to communicate the psychological toll of his environment. It is a raw, often silent performance that anchors the film’s high-concept horror in human vulnerability.

The supporting cast is primarily experienced through voice-over and comms, which places a heavy burden on the audio performances. Caroline Rose Kaplan provides a necessary tether to the world outside as Ava, though her character remains somewhat distant, perhaps intentionally so to heighten Simon’s isolation. The inclusion of Seán McLoughlin and the legendary Troy Baker adds a layer of gravitas to the world-building, with Baker’s "Father" figure providing a dire, paternal voice-over that sets a grim tone from the opening frames. These performances create a sense of a larger, dying civilization existing just beyond the steel walls of the sub, even if the chemistry between characters is limited by their physical separation.

Direction and Technical Aspects: The Art of the Bleeding Machine

Fischbach’s vision for Iron Lung is surprisingly focused for a first-time feature director. He avoids the pitfall of many YouTuber-led projects by fully committing to a gritty, high-fidelity aesthetic that feels lived-in and dangerous. The cinematography by his team utilizes the overhead shot effectively, particularly in the opening sequence where the submarine is lowered into the roiling red sea like a piece of bait. The visual composition within the sub is masterful, using a palette of oppressive reds and sickly oranges to create a constant state of visual alarm.

The production design is the true star of the film. The Iron Lung submarine is a masterpiece of practical effects and set construction. Every dial, light, and monitor feels functional and heavy, contributing to a "low-tech" sci-fi vibe that is far more terrifying than a sleek, futuristic vessel would be. As the mission progresses, the sub begins to sweat and eventually "bleed," with liquid seeping through the rivets. This transformation of the vessel into a biological-mechanical entity is a highlight of the film's visual storytelling. The editing keeps the viewer trapped alongside Simon, refusing to cut away to the safety of the surface for long stretches of time.

Trailer Iron Lung (2026)

Music and Atmosphere: A Symphony of Metal and Blood

The sound design of Iron Lung is arguably its most effective horror tool. The film understands that in a windowless environment, sound is everything. The constant creaking of the hull, the rhythmic thumping of the sonar, and the unsettling splashes of the blood ocean outside create an immersive auditory experience. When the silence finally hits, it feels heavy and suffocating. The score is minimalist, often blending into the industrial ambient noise, which prevents it from becoming a distraction and instead allows it to slowly dial up the audience's heart rate.

The mood is one of unrelenting cosmic dread. By blending the fear of the unknown with the very physical fear of being crushed by pressure, Fischbach creates an atmosphere that is uniquely uncomfortable. The film doesn't rely on cheap jump scares, instead building a slow-burn terror that stays with you long after the credits roll. The sheer amount of blood used in the final act—rumored to be a massive portion of the production budget—is used effectively to create a visceral, almost nauseating sense of climax.

Strengths and Weaknesses

Strengths

• The practical set design of the submarine is incredibly detailed and immersive.
• The central concept of the "Quiet Rapture" is a brilliant piece of cosmic horror lore.
• Atmospheric sound design creates a constant, low-level sense of panic.
• Mark Fischbach's lead performance is committed and physically grounded.
• The visual effects regarding the "bleeding" sub are genuinely unsettling.

Weaknesses

• At 125 minutes, the film feels overstretched for its relatively simple narrative.
• The plot involves repetitive tasks and navigational loops that can test viewer patience.
• Many of the film's largest mysteries are left entirely unexplained.
• The excessive use of gore in the final act may feel gratuitous to some viewers.

Final Verdict: A Bold Experiment in Isolation

Rating: 3.5/5 stars

Iron Lung is a fascinating, if flawed, foray into big-screen horror from one of the internet's most recognizable faces. It succeeds wildly as a technical showcase, proving that a compelling film can be built almost entirely within a single, claustrophobic room. Fischbach demonstrates a keen eye for tension and a deep respect for the horror genre's ability to explore existential themes. While the pacing issues and the narrative's refusal to provide clear answers might alienate those looking for a standard sci-fi thriller, the film’s commitment to its grim vision is admirable.

Fans of the original game, enthusiasts of "contained" horror movies like Buried or Locke, and those who enjoy cosmic dread will find a lot to love here. However, viewers who struggle with slow pacing or who require a clear, logical conclusion to their mysteries might find themselves feeling as trapped as the protagonist. Ultimately, Iron Lung is a visceral, bloody, and deeply atmospheric journey that marks a promising start for Fischbach’s cinematic career.