Mark Fischbach — better known as Markiplier — has done the unthinkable. The YouTube superstar wrote, directed, produced, edited, self-financed, and starred in his own feature-length horror film, Iron Lung, and the results have taken Hollywood by surprise. From a grassroots theater campaign to a $51 million worldwide box office gross, Iron Lung has become one of the most talked-about independent films in recent memory. Here is everything you need to know.
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What Is Iron Lung? The Game Behind the Movie
Before it was a film, Iron Lung was a deeply unsettling indie horror game released in 2022 by solo developer David Szymanski. The game placed players inside a sealed submarine — called the “Iron Lung” — navigating a moon covered entirely by an ocean of blood. With no windows and only a crude camera for sight, the game became a cult classic in horror gaming circles. Markiplier, who had played the game on his YouTube channel to millions of viewers, fell in love with the premise and decided to adapt it into a full-length film.
The Plot of the Iron Lung Movie
Set in a distant, post-apocalyptic future, Iron Lung centers on a catastrophic event called “The Quiet Rapture” — a mysterious occurrence that causes all stars, planets, and most of humanity to vanish without warning. Only those aboard space stations and starships survive.
Simon, nicknamed “the Butcher,” is a convict imprisoned for his role in destroying a space station. As punishment — and with freedom as his reward — he is forced to pilot the SM-13 submarine (the “Iron Lung”) deep into an ocean of blood on a desolate moon. The porthole is welded shut. Simon can only see outside using a still-image camera, and his only contact with the surface crew comes through a crackling radio. What he photographs during the dive drives the film’s creeping dread.
The Cast
- Mark “Markiplier” Fischbach — Simon (the lead)
- Caroline Rose Kaplan
- Troy Baker — a standout performance despite limited screen time
- Elsie Lovelock
- Elle LaMont
- Mick Lauer
- Seán McLoughlin (Jacksepticeye)
- Isaac McKee
- Alanah Pearce
Production: Blood, Sweat, and Three Years of Work
Pre-production began on February 7, 2023, with filming starting March 7 and wrapping May 1 — shot entirely at Troublemaker Studios. Markiplier confirmed the film contains more fake blood than any horror movie ever made, surpassing the 50,000 gallons used in the 2013 remake of Evil Dead. The final count? Over 80,000 US gallons of fake blood. During production, Markiplier had to be taken to the hospital after getting too much of it in his eyes.
Filming was completed by April 29, 2023, but production was significantly delayed by the 2023 SAG-AFTRA strike — Markiplier, a union member, halted work out of solidarity. By June 2024, the film was finally declared done, with Markiplier entering distribution negotiations.
The film was made on a $3 million budget — an extraordinary constraint for a theatrical horror film.
Release: From 60 Theaters to Over 4,000
On December 5, 2025, Markiplier dropped the final trailer and opened ticket pre-sales, coinciding with the film’s Los Angeles premiere at Alamo Drafthouse Cinema Downtown. The initial plan was a modest run of 50–100 independent theaters.
What happened next was unprecedented. Fans launched a grassroots campaign, contacting local theater chains directly and demanding screenings. Within days, Iron Lung had expanded to Cinemark, AMC, and Regal, and by the official release date of January 30, it was showing in 4,161 theaters internationally across North America, the United Kingdom, Australia, New Zealand, and parts of Europe — distributed by Piece of Magic Entertainment.
Some theaters partnered with local blood donation centers for opening weekend, aiming to break the world record of 37,000 donations.
In March, Warner Bros. India acquired domestic distribution rights following a fan-led campaign, and the film opened in Indian theaters on March 13.
Box Office Performance
Iron Lung has been a genuine box office phenomenon for an independent, creator-led film:
- Opening weekend: $8.9 million (including $3.5 million in Thursday previews)
- Domestic gross (US & Canada): $41 million
- International gross: $10 million
- Worldwide total: approximately $51–52 million
Despite losing the overall weekend box office crown to the studio-backed Send Help, Iron Lung actually pulled in more admissions — 1.9 million for the week vs. Send Help‘s 1.7 million — simply because its average ticket price ($12.86) was lower due to the absence of premium large-format screens. It is now ranked among the top 5 highest-grossing horror films of the year and considered one of the biggest indie hits in recent memory.
Critical Reception
Iron Lung holds a 6.5/10 rating on IMDb, reflecting the mixed-but-passionate response from audiences. Critics and viewers have praised:
- The sound design and atmospheric tension
- The claustrophobic cinematography, especially impressive given the film takes place almost entirely inside a single room
- Markiplier’s lead performance, described as genuinely committed
- Troy Baker’s standout supporting work
The main criticisms center on pacing during navigation sequences and a backstory that some feel is thin relative to the ambition of the premise. Creator of the original game, David Szymanski, has clarified that the film is “a separate canon from the game, at least for now.”
What’s Next: Digital, DVD, and Blu-ray
True to his independent spirit, Markiplier is self-distributing Iron Lung on home media as well. He has announced plans to make the film available for digital purchase and rental on YouTube Movies, and is simultaneously working to build a system that allows other independent filmmakers to distribute their own films through YouTube — a move that could reshape creator-led filmmaking.
For physical media, Markiplier has confirmed he will literally run a DVD and Blu-ray machine from his home, producing copies of Iron Lung himself. The idea reportedly came from his wife, Amy Nelson.
Why Iron Lung Matters Beyond the Box Office
Iron Lung is more than a horror film — it is a proof of concept. Markiplier demonstrated that a content creator with a loyal fanbase, an ambitious vision, and complete creative control can compete with major studio releases. The grassroots theater expansion, the self-distribution model, and the blood donation campaigns all point to a new kind of relationship between creators and their audiences.
For horror fans, it is a tense, claustrophobic experience that rewards patience. For the film industry, it is a case study in what happens when a creator refuses to be told something “can’t be done.”
As Markiplier himself put it when the project was announced: “They said it shouldn’t be done. Not that it couldn’t be done — just that it would be ‘woefully unwise’ to tackle writing, directing, acting and editing a movie myself. Showed them.”
Frequently Asked Questions
Is Iron Lung available to stream? Not yet, but Markiplier has confirmed a digital release on YouTube Movies is coming soon, along with a DVD and Blu-ray release.
Is Iron Lung based on a true story? No. It is based on the 2022 indie horror video game of the same name by David Szymanski.
How much did Iron Lung make at the box office? Approximately $51–52 million worldwide on a $3 million budget.
Who else is in the Iron Lung movie? The cast includes Troy Baker, Elsie Lovelock, Caroline Rose Kaplan, and Seán McLoughlin (Jacksepticeye), among others.
Is Iron Lung rated R? Yes. The film is rated R for strong language and gruesome scenes.
