Markiplier’s Iron Lung film turns a one-hour indie submarine game into a feature-length descent through an ocean of blood. Here are the hard facts you came for: when it hit theaters, when it went digital, how long it runs, what it’s rated and how the box office story actually works for a self-funded horror movie.
What to know in 30 seconds
| Detail | The answer |
|---|---|
| Title | Iron Lung |
| Director and writer | Mark Fischbach (Markiplier) |
| Based on | Iron Lung (2022), the PC game by David Szymanski |
| US theatrical release | January 30, 2026 |
| Digital release | Followed the theatrical run; now available to buy or rent |
| Runtime | Feature length, a little under two hours |
| Rating | R |
| Genre | Claustrophobic sci-fi horror, submarine survival |
| Funding | Independently financed by Fischbach, no studio |
Iron Lung movie release date
The film opened in US theaters on January 30, 2026. That date matters more than it sounds. Fischbach did not sell the movie to a studio. He paid for it, directed it, starred in it and then arranged the theatrical booking himself, which is close to unheard of for a first-time filmmaker whose main audience lives on YouTube.
Because there was no traditional studio window, the home release came quickly after the theatrical run rather than months later. The film is now on digital storefronts to buy or rent. If you want it on a subscription streaming service, that deal has not been announced as of this writing, so your options are a ticket, a purchase or a rental.
If you are following other internet-born horror making the jump to cinemas, the “backrooms film release date” is the one to watch next. Kane Parsons’ A24 adaptation is the closest comparison to what Fischbach pulled off here, just with a studio behind it.
Iron Lung trailer: what it showed
The trailer landed in late 2025 ahead of the January date and did one thing very well: it refused to show much. You get the cramped interior of the sub, Fischbach in a convict’s jumpsuit hunched over an instrument panel, the red glow of the hull lights and a lot of metal groaning under pressure. The only exterior shots are brief, murky and shot from inside the viewport, which is exactly how the game handles it.
That restraint was a deliberate choice. The game’s horror runs on what you cannot see. The trailer treats the blood ocean the same way, cutting to black on sound cues rather than money shots. There is one glimpse of the camera flash illuminating something outside the hull, and that single frame did most of the heavy lifting in getting people into seats.
The trailer also confirmed the film’s tone is heavier than people expected from a YouTuber project. No winks at the audience, no meme references, no cameo-hunting. It plays it dead straight.
How long is Iron Lung?
The movie runs a little under two hours. That is a big expansion of the source material, since a careful playthrough of the game takes roughly an hour and a speedrun is far shorter.
Fischbach filled that extra time in two ways. First, there is more context around who the convict is and why he, specifically, is the one being lowered into the blood. The game never names the player character and barely explains the sentence that got him there. Second, the film expands the world above the sub: the people giving the orders, the state of the stations that survived and what is really being asked of the man inside the Iron Lung.
Check your listing before you go, because some theaters bundle pre-show content into the advertised time. The feature itself does not hit the two-hour mark.
Iron Lung rating and content
The film is rated R in the US. Expect blood in quantity (the whole ocean is made of it), some genuinely nasty body horror late in the running time, and strong language. There is no sexual content.
What the rating does not capture is the sustained pressure. Nearly all of the movie takes place inside a single rusty hull. If you struggle with tight spaces, you will have a harder time with this than with something far gorier. Gore-sensitive viewers can manage most of it, with a couple of look-away moments in the final act.
The honest scare rating is 3 out of 5. It is not a jump-scare machine. It is a slow tightening of a vice, closer in spirit to The Descent (2005) or Underwater (2020) than to a modern Blumhouse picture.
Markiplier Iron Lung box office: how to read it
This is where the usual box office rules do not apply, so the headline number you see quoted anywhere needs context.
A studio horror release at $40 million needs to clear roughly two and a half times that worldwide before anyone makes money, once marketing and the theater’s cut are included. Iron Lung had no studio, no major marketing spend and a budget that Fischbach has described as coming out of his own pocket. He also said publicly before release that he expected to lose money and was fine with that.
What that means in practice:
- The theatrical run was always going to be modest in screen count compared to a wide release.
- A per-screen average, rather than the raw total, is the better measure of how the film performed.
- Digital sales and rentals, where the filmmaker keeps a much bigger share, are where the real recoup happens.
For the current running tally, Box Office Mojo and The Numbers both track it under the 2026 release. Any figure quoted here would go stale within days, so check those for the live total. The short version: the film did not need a blockbuster weekend to count as a success, and it sold far better than the “YouTuber vanity project” dismissals predicted.
Cast and crew
Mark Fischbach writes, directs, produces and stars as the convict. If you only know him as Markiplier from Let’s Plays, the performance will surprise you. He spends most of the film alone, in a space barely larger than a phone booth, with nothing to act against except gauges and a crackling radio.
Caroline Rose Kaplan plays the main voice on the other end of that radio, the operator who feeds the convict his coordinates. Her scenes carry most of the film’s human weight.
Seán McLoughlin, better known as Jacksepticeye, appears in a supporting role. It is not a stunt cameo; he is there as an actor.
David Szymanski, the game’s creator, was involved as a consultant and is credited for the original work. Szymanski also made Dusk (2018) and Gloomwood, which matters because his whole design philosophy is “small, cheap, terrifying,” and Fischbach clearly absorbed it.
The practical submarine interior was built as a full set rather than a green-screen box. Fischbach documented the build on his channel during 2023, and it shows on screen: every dial and valve is a real object the camera can get close to.
The game it is based on
Before you watch, it helps to know what Iron Lung the game actually is, because the film inherits all of its rules.
David Szymanski released Iron Lung on Steam on March 10, 2022, for a few dollars. It later came to Nintendo Switch. You play an unnamed convict sealed inside a tiny submarine and lowered into an ocean of blood on a nameless moon. There is no window you can look through in real time. Instead, you have a proximity sensor, an X and Y coordinate readout, and a camera that takes one grainy photograph at a time of whatever is directly ahead.
Your job is to reach a series of coordinates, photograph what is there and get out. That’s it. The entire game is you, a map scrawled on paper, and the sound of the hull.
It became a phenomenon because of how it uses silence. Most of the hour nothing happens. Then the proximity alarm goes off and you have no idea what tripped it. Fischbach’s own playthrough in 2022 is a large part of why the game sold as well as it did, and it is the reason the film exists at all. If you want to play it first, it sits near the top of any honest list of short “pc horror games” and runs on basically anything.
The premise, spoiler-free
The backstory is the part people get wrong, so here it is straight.
An event called the Quiet Rapture happened. Every star and every planet simply vanished. No explosion, no warning. Humanity survived only on the scattered moons and space stations that were far enough from the planets to be left behind. Those survivors are now running out of everything.
Then someone discovered that one small, nameless moon has an ocean. Not water. Blood. Nobody knows whose, or what, or why. The only way to explore it is a rusty, ramshackle submarine nicknamed the Iron Lung, never built for that depth, and the person expendable enough to pilot it is a convict who has been promised his freedom in return. Survive the dive, take your photographs, and you walk free.
The film keeps every piece of that. It gives the stations and the people on them more screen time, but the central engine is the same: one man, one sub, one ocean, and a camera that shows you things you would rather not have seen.
What the film changes from the game
Spoiler warning
The next few paragraphs discuss the ending of the 2022 game and how the film reworks it.
The game ends abruptly. You reach your final coordinates, something enormous slams into the sub, the lights fail and the last photograph you take shows a face, or at least a mouth, far larger than the submarine. The screen cuts to the sound of the hull giving way. Players spent years arguing over what the thing was, whether the blood ocean was alive, and whether the convict ever had a real chance.
The film does not simply replay that. Fischbach extends the final act past the point where the game stops, which is the single biggest departure from the source. You get more of the creature than the game ever showed, and that choice splits fans. Some wanted the mystery preserved. Others felt a two-hour movie could not fade to black on a single photograph the way a one-hour game can.
The film also answers the question of what the people on the surface stations actually wanted from the dive. The game leaves you assuming it was simple exploration. The movie makes it clear the mission was never quite that, and that reveal recontextualizes Kaplan’s radio scenes on a rewatch.
The Quiet Rapture itself stays unexplained. Good. Explaining it would have killed the whole thing.
Critics vs audience: why the reviews split
Reviews for Iron Lung broke along a predictable line, and it is worth understanding why before you let a score decide for you.
Professional critics mostly judged it as a debut feature and found the middle stretch slow. They are not wrong that the film spends a long time inside the sub with little dialogue. That is the point, but it is a hard sell to someone who has not played the game and does not already feel the dread of the proximity alarm.
Audiences, especially the game’s fans, rated it far higher. They came in knowing the rules, so the quiet stretches read as tension rather than dead air. The practical set, the sound design and the fact that Fischbach treated the material with total seriousness landed hard with that crowd.
A fair middle position: this is a confident, ugly, genuinely frightening horror movie with a saggy second act and an ending that gives away a little too much. For a first film made outside the studio system, that is a strong result.
Why this release matters
Iron Lung is the first time a creator with a YouTube audience of that scale wrote, directed, financed and starred in a theatrical feature without a studio partner. The lesson other creators will take from it is not “make a movie.” It is “make a small movie about one idea and own the whole thing.”
It also proves the micro-horror adaptation model works. The game cost a few dollars, took an hour, and had one location. That is a cheap film to make and a very hard film to make well. Fischbach made it well enough that the next wave, including the Backrooms adaptation, now has a precedent.
What happens next
Fischbach has said he has more film ideas but has not announced a second project. There is no sequel to the game, and Szymanski has shown no interest in making one, so a direct follow-up is unlikely.
The more realistic next step is a streaming deal. Independent films in this position usually land on a subscription service within a year of digital release. When that happens, the most likely homes are Shudder or a general service picking up horror for its October slate.
In the meantime, the game remains the best companion piece. Play it, then watch the film, then play it again. The film’s expansion of the backstory makes the game’s silences feel heavier the second time.
If you liked this
Underwater (2020) for the same deep-pressure dread with a bigger budget and Kristen Stewart. The Descent (2005) for claustrophobia that turns into something far worse. Sea Fever (2019) for slow, quiet, boat-bound horror where the real enemy is what you cannot see in the water.
If the isolation and mind-games side hooked you more than the creature, the “psychological thriller” end of horror is worth exploring next, since that is where Iron Lung’s middle hour really lives.
FAQ
When did the Iron Lung movie come out?
It opened in US theaters on January 30, 2026, and moved to digital purchase and rental after the theatrical run.
Is Iron Lung streaming anywhere?
Not on a subscription service yet. You can buy or rent it on the major digital storefronts. A streaming deal is likely but has not been announced.
How long is the Iron Lung movie?
A little under two hours. The game it is based on takes about an hour to play.
What is Iron Lung rated?
R, for blood, body horror and language.
Do I need to play the game before watching?
No, the film explains the Quiet Rapture and the mission on its own. Playing first does make the quiet stretches hit harder, and the game is short and cheap.
Is Markiplier actually in it?
Yes. Mark Fischbach wrote, directed and plays the convict. Seán McLoughlin (Jacksepticeye) has a supporting role.
Did Iron Lung make money at the box office?
It was self-funded with no studio, so it never needed blockbuster numbers to turn a profit. The theatrical run performed well for its screen count, and digital sales are where most of the return comes from. Check Box Office Mojo for the current total.
Is there a sequel to the Iron Lung game?
No. David Szymanski has moved on to other projects, and the film does not set up a continuation either.