‘Iron Lung’ Review: Markiplier’s Slow Burn Video Game Adaptation Offers a Fascinating, Flawed Experiment

Telling yourself “This is bigger than us” proves an essential survival tactic in “Iron Lung.” Not just for the sci-fi film‘s doomed protagonist — welded inside a rusty submarine and forced to explore a literal ocean of blood to win his freedom — but also for the various audiences navigating YouTuber Markiplier‘s exhausting and ambitious feature debut finally in theaters this weekend.

In this grueling single-location thriller, adapted from David Szymanski’s 2022 horror game, filmmaker/star Mark Fischbach (known online as “Markiplier”) traps viewers alongside himself as Simon, a prisoner aboard the space station Eden. Reeling after a mass-casualty event known as the Quiet Rapture, humanity’s last stand is just the starting block for a project that demands endurance before it delivers immersion, ultimately revealing the promise and peril of creator-led video game adaptations at scale. At times, the 36-year-old director seems to mistake fan loyalty for limitless attention, and he risks his young audience with a nightmare that’s admirable but likely too taxing for that demographic.

Seen out of context, “Iron Lung” plays like a bleak cousin to Duncan Jones’ “Moon” from 2009, though it’s sorely missing that indie darling’s singular score and expansive visual mythology. Embarking on an expedition so dangerous it resembles an execution, Simon must chart the gaseous bedrock of a crimson-red alien moon — or die trying. True to the video game, the camera never leaves the Iron Lung (a mini-sub with a dark past), and that choice may come as a shock to viewers unfamiliar with the source material. Embracing that constraint takes real patience and a willingness to accept a rhythm defined by claustrophobia over escalation.

“Iron Lung” Courtesy Everett Collection

A beloved influencer in the gaming world, Markiplier’s commitment to loyal adaptation is absolute in spirit but near-impossible in execution when it comes to a property as opaque as “Iron Lung.” The main character is a nameless avatar in the original telling. Neon-green digital readouts, dripping blood, three-ring binders full of technical instructions, and endless close-ups of the navigation system ground the movie in tactile realism but rarely ignite imagination. The result is not self-important so much as punishingly sincere, a movie that believes so deeply in its process that it neglects cinematic momentum. “Iron Lung” runs over two hours, making for a slew of baffling editing decisions (Markiplier also cut the film) that turns suspense into stasis.

That length exposes Simon himself as the film’s primary weakness. Written as an expanded version of the player character in the game, he never quite becomes a person despite being played by a world-famous internet personality. His guilt over a mysterious incident at a place called Filament Station and his capacity for violence as a survivor of the apocalypse are gestured at rather than explained, leaving Simon more vessel than hero. The script leans heavily on exposition — internal monologues, disembodied intercom voices, and hallucinatory flashbacks — to communicate lore that might have resonated more powerfully through action or environment. Some of the game’s most evocative writing, blending cosmic horror with humanity’s loss of faith in itself, gets swallowed by that verbal density.

“Iron Lung”Courtesy Everett Collection

Earnest and likable but never quite enough to make Simon a proper person, Markiplier’s performance compounds that problem. Separated from his online platform, the film’s star reveals himself as an actor still acquiring the necessary tools for emotional subtlety. He relies on small facial expressions that never quite land, and his authentic expletive-laced frustration builds a certain kinship with the character. That said, it also underscores how much of Markiplier’s appeal on YouTube comes from reacting to external challenges. The knowing masochism that makes watching him play difficult or scary video games compelling doesn’t translate cleanly when he is the architect of his own haunted house. Simon exists in “Iron Lung” against his will, and that disconnect steadily suffocates its star. 

And yet, “Iron Lung” is far from a failure. Measured against the graveyard of other video game adaptations — especially recent studio misfires like Cineverse’s “Return to Silent Hill” — this deeply flawed attempt still stands as a testament to what happens when actual gamers make video game movies. Its imperfections are heartfelt, not cynical, and it’s clear that significant effort was put into acquiring the right team for this production. Cinematographer Philip Roy finds texture in near-total darkness, and composer Andrew Hulshult’s score, drawing on his celebrated work in the games world (“Doom Eternal,” “Dusk”), provides a confident undercurrent the imagery often lacks. The most effective moments arrive when the Iron Lung’s massive camera flashes black-and-white images of the abyss outside, delivering jump-scares that feel genuinely viral. 

But again, the editing is where the experiment truly falters. Shots linger long after they’ve communicated their information, turning repetition into dead weight, and repeatedly staring at a gore-splattered GPS makes the mission feel like a maddening endless road trip. When an intercom announces Simon has 30 minutes left to complete his task, the dominant fear stems less from narrative stakes than from the realization that there is so much movie left to go. 

“Iron Lung”Courtesy Everett Collection

Ambiguity, a strength of the game, becomes a liability. The film teases monsters, human remains, and lost vessels without letting the audience experience the world beyond the hull. That restraint could have functioned as thematic isolation, but instead it often reads as under-resourcing. Whether the missing ingredient was money, source material, or bold creative swings is difficult to parse; what’s obvious is that too little concept has been stretched too far.

The theatrical experience, however, reframes the entire project. In a packed early screening dominated by Markiplier fans, the atmosphere resembled a communal livestream more than a traditional moviegoing environment. Credit names, including those of some Markiplier’s collaborators, drew louder reactions than many of the movie’s horror beats. Some viewers filmed the screen or chatted through stretches of the runtime, behaviors that would curdle a more cinephilic crowd but felt organic to a fandom accustomed to shared, participatory viewing. That subculture undercuts escapism but proudly points to a different kind of theatrical future.

Crucially, Markiplier does not pander to his own audience with in-jokes or winks like you’d find in a “Five Nights at Freddy’s” flick. (It’s worth knowing that the YouTuber played an integral role in popularizing those games and later films, and establishing the audience-based distribution model we’re seeing work again now.) “Iron Lung” is a punishing attempt at artistry, made harder for Markiplier by the decision to direct himself while self-distributing on more than 2,500 screens. Compared to similar efforts that haven’t done as well financially or critically, the film stands out for taking itself seriously. It’s slow, detail-obsessed, and aware enough of its shortcomings not to overplay them. Markiplier never feels self-aggrandizing and he’s got the smarts to know when to cut away, even as he allows his film’s setting to fester beyond catharsis.

As a case study, “Iron Lung” may matter more than it entertains. This fascinating stress test suggests that video game adaptations could thrive when entrusted to web-native creators who not only respect but understand their source material — and would benefit from collaboration with more experienced filmmakers. It also forecasts a movie world where audience trust functions as infrastructure, enabling theatrical releases that bypass traditional marketing entirely. That’s not replicable for most filmmakers, but its existence nevertheless reshapes conversation.

“Iron Lung” is audacious and at times astonishingly boring. Still, it feels more enthusiastic and celebratory than many blockbuster adaptations built on safer math. Insisting that the mission is bigger than any one person, including its creator, the film opens space for more daring, messy attempts to follow. For indie cinema, that alone may be worth the ordeal… if not, the gallons of blood.

Grade: C+

From Markiplier Studios, “Iron Lung” is in theaters January 30.

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