Adapting a video game for the big screen is always hit or miss. While at this point in the zeitgeist we’ve had successful film adaptations of video games, “Iron Lung” stands apart. But unlike your typical video game adaptation, “Iron Lung” was created by a YouTuber, not an established studio. Despite this, it’s been a box office hit.
“Iron Lung” is a horror film directed by, written by, and starring video creator Mark , professionally known as Markiplier. The film is based on the 2022 indie game of the same name created by David Szymanski.
Markiplier rose to popularity in 2014 on YouTube and found great success in uploading videos of himself playing horror games, where people would watch to see his reactions.
Thirteen years later, Markiplier has taken on multiple creative projects and has expanded outside the YouTube realm. In 2022, Markiplier created a YouTube original movie, “In Space with Markiplier,” that let viewers decide how the film would play out by pre-taping separate takes that would be different based on viewers’ choices.
During that time, Markiplier got to see the limitations of working with a studio. He said in a later interview with IGN,“There are a lot of inefficiencies in the system. I do believe that there are so many more technological advances that allow for more people to make higher level things easier.”
According to Markiplier, the only separation between what he does on YouTube and what he does with his film is skill, editing-wise. You can see this efficient mindset at play as Markiplier stars, directs, writes, and edits for the “Iron Lung”, taking full advantage of the skills he’s developed making YouTube videos.
Before I went to see “Iron Lung,” I bought the game for $4 on Steam and booted it up in five minutes. The premise is that the stars are all going out and that you, a convict, have been sealed inside a scrap submarine to explore an ocean of blood. You have no way to see outside except a camera on the opposite side of the ship from the controls that lets you see what’s right in front of you.
I got my first “ending” of the game when I accidentally ran the submarine into a wall, killing my character instantly. Because I couldn’t see what was happening around me, I started making a mental map of where I was the more I played. This trick works because Szymanski created a labyrinth for you to travel through — although only a camera bobs through the labyrinth while the player in a separate room controls its movements.
At certain places in the blind labyrinth, Szymanski plays audio outside of the submarine to make the player feel like they aren’t alone. My entire submarine vibrated as it (or I) passed an anomaly that pulsated so loudly I could hear it through the walls. At another point, I had to go through a narrow crevice, navigating the submarine carefully so as to not hit the walls when my sensors detected something in front of me. I activated my camera only to see a giant eye staring back at me, and my submarine shook as whatever I saw pushed past me.
The film version of “Iron Lung” follows the same premise as the game, but with twice as much screentime. Certain details, like explaining how the camera uses X-ray radiation to take pictures through an ocean of blood, fill in gaps the game doesn’t.
Markiplier plays Simon, the unlucky convict trapped inside the submarine. At first, I could only imagine Simon as Markiplier, the online persona, but as the film went on, I was quickly immersed in what was happening. I never quite forgot that this was a film featuring Markiplier, but I did forget that he made it.
Unlike most films, there are no studio credits before the film starts. Part of the reason I think the film works well is that it takes place entirely inside the submarine, which, for the most part, closely resembles its game counterpart. While I would say the film is more bombastic than the game is, there is plenty of slow burn to the film that, at times, feels unnecessary. There are many intense close-up shots of water droplets on the side of pipes — perhaps too many.
By the time the climax is close, it is all killer no filler. “Iron Lung” makes clear that it’s not just horror, but the cosmic horror that can only happen in a submarine at the bottom of a blood sea. As Simon’s oxygen depletes more and more, he begins hallucinating, and the camera’s objectivity on reality starts breaking down.
“Irong Lung” is not the best horror movie of the year, but it is the best movie for its origins. There is no roster of films to compare it to that were inspired by niche horror games that were picked up by people who play them and turned into films. “Iron Lung” cost $3 million to produce and as of Feb. 16, 2026, has made $43 million worldwide.
Movies trying to make a quick buck by using YouTube fame often crash and burn, but “Iron Lung” is something different. I think that as a proof of concept that good YouTuber movies can be made. However, once I start judging it as a film, I think it could’ve done more. To Markiplier’s credit, I don’t think he was trying to make a perfect, or even commercially successful, film.
His IGN interview ends with him giving a call to action to creators to challenge the notions of what they can do by finding more effective avenues of production. He ends it by saying, “Not everything is about making a profit. If you can break even on something and you made something cool, that adds value to the world.”
In many ways, “Iron Lung” misses the mark with how it paces its storytelling; however, in daring to tell its story the way it did, it is an absolute success.
