Published:
Readtime: 7 min
Every product is carefully selected by our editors and experts. If you buy from a link, we may earn a commission. Learn more. For more information on how we test products, click here.
To say the first week or so of Iron Lung‘s run at the box office has been a rollercoaster would be an understatement. Somehow, a film funded, directed, and led by Mark ‘Markiplier’ Finsbach (one of the biggest YouTubers on the planet), managed to spend most of its time in cinemas as the no. 1 grossing movie in the United States, Australia, Canada, New Zealand, and more.
The film has crested USD$21 million worldwide, and cemented itself as the 6th biggest release of the 2026 so far—and its theatrical run has been extended in many theatres, meaning it can only get better for Markiplier’s baby.
Without any studio backing, or marketing really, the film has outperformed any possible expectations that were placed on it: grossing around eight times its budget (so far) and going toe-to-toe with Sam Raimi’s return to the horror genre, Send Help, which did eventually overtake Iron Lung as the no. 1 film in US cinemas.
But, there’s a wrinkle. On the whole, critics haven’t particularly liked the movie, while audience scores are quite a bit more positive. Is it just Finsbach’s gigantic audience of 38 million dedicated fans supporting his indie film, or are the critics wrong?
What is Iron Lung?
If you’re not entirely sure what Iron Lung is, it tells the story of Simon, a convict who is sealed inside a submersible to delve deep into an extraterrestrial blood ocean to search for anything that can help what remains of humanity survive an event that has effectively extinguished every star in the known galaxy.
That mirrors the events of the 2022 game the film is based on—also called Iron Lung—which was created by solo dev David Szymanski. In the original, you pilot the submersible through the blood ocean searching for anything of interest, and the more you see, the more dangerous the salvage operation becomes. It’s not an action-packed game by any means, instead generating a slow sense of unease in the player as they themselves have to willingly dive deeper into an unknown and alien space that is clearly home to something other than yourself. It’s not overly long—you can finish it up in just a few hours—but it left a lot of purposefully unanswered questions while also setting up the foundations for what remains of this world. That world clearly resonated with Markiplier.
The movie took him the better part of two years to pull together, produce, and finally distribute into cinemas, and it has the Guinness World Record for ‘most fake blood used in a movie’, with a staggering 300,000 litres used to really sell the idea of an encroaching blood ocean.
What Do The Critics Say?
On the whole, critics of Iron Lung call out the film for being too long (with a runtime of over two hours) and slow, with an over reliance on a single set, a sparse narrative, and sometimes awkward acting.
IGN noted that while the movie’s mere existence was impressive, as is Finsbach’s passion for the source material, the actual film isn’t.
“If only the passion…translated into something far more interesting on screen. Because wow, is Iron Lung a slog to get through,” IGN said. “(It) has terrible pacing and very low energy from the start.”
RogerEbert.com added to that, noting that the film’s reverence for the source material sets it up for a punishing pace, and that Finsbach’s characterisation of Simon is lacking, usually moving between “stressed and more stressed”, but that the technical aspects of the film are fantastic.
Similarly, Empire noted monotonous pacing and the film’s extended run-time, stating that the movie probably would have been better as a short. “This low-budget sci-fi horror makes Event Horizon look like 2001: A Space Odyssey.”
Each of these reviews also noted the film’s confusing story, which, in keeping with the source material, poses as many questions as it does answers. Finsbach joked that he made the movie confusing in order to encourage people to watch it again, but that non-linear style of storytelling clearly didn’t impress critics. It’s likely easier to understand the events of the film if you’ve already played the game and understand the basic building blocks of the world. But even so, it’s clear the film is being purposefully vague with details. Finsbach co-wrote the film with Szymanski, meaning there’s no reason to think the vague story isn’t intentional.
Polygon noted that many reviews by established outlets seem to have compared Iron Lung to a ‘conventional’ horror film—going in looking for jump scares and a tension-and-release structure, which isn’t quite what the film is about. Instead, the film is going for a creeping, existential dread common in the cosmic horror genre, rather than the sudden excitement often used in major horror films. Whether you like that slow dread is up to you, but many critics didn’t.
In saying that, effectively all critics were impressed by the film’s direction and technical aspects, with particular praise put on the ambition and creativity on display. For a two-hour film trapped almost entirely with a claustrophobic submersed coffin, Finsbach sure gets a lot of mileage out of that set through clever camera work and attention to detail.
What do Audiences Think of ‘Iron Lung’?
Audience reviews, though, are a different beast. Markiplier’s fans are, obviously, effusively excited that the long-awaited adaptation is out in theatres, and are leaving review scores accordingly. The YouTuber’s subreddit is awash with mostly positive sentiment, with fans already breaking down secrets and hidden details in the film, comparing them to the original game to try to understand the dystopian, apocalyptic world a bit better.
Even beyond his impressed fans, though, general audiences seem to be enjoying the film. Compared to the 54% ‘tomatometer’, which is dictated by a small number of critics, Rotten Tomatoes‘ audience-driven ‘popcornmeter’ sits at 90% with well over 1,000 ratings.
The question as to how much of this is simply Markiplier’s audience propping the film up is difficult to answer: with an audience of 38 million people around the world, many of whom feel a parasocial bond to the filmmaker, it’s easy to imagine a few thousand of them leaving positive reviews to boost the film’s scores.
But that wouldn’t necessarily explain the box office performance. The year is still young, but Iron Lung has already performed better than anyone could have anticipated: sitting at number 6 in the world-wide box office figures for 2026, behind Greenland 2, Send Help, Primate, Mercy, and 28 Years Later: The Bone Temple—all films with much bigger production and marketing budgets.
This, to Finsbach, is the biggest victory of all. Talking to The Hollywood Reporter, he said he faced quite a bit of pushback from the industry at large during production, with several large studios effectively laughing him out of the room, doubting the film’s ability to draw in a sizeable crowd. He also faced difficulties getting theatre owners to even show the film, as without a distributor he had to rely on word-of-mouth—something that his audience definitely helped with, calling local theatres to request they show the film to the point many owners thought it was a targeted bot campaign.
It wasn’t. It was genuine demand by an audience that voted with their wallet when push came to shove.
Iron Lung is showing in select cinemas now.
Comments
We love hearing from you. or to leave a comment.