A review of Markiplier’s “Iron Lung”
“This is not an expedition. It is an execution. When they put you in here, they don’t want you to return. And even if you do, and even if they keep their promises… what freedom waits for you? A few dying ships in a sea of dead stars? If there is still hope, it lies beyond the veil. Hope in this void is as illusionary as the starlight. I will choose to breathe my last here at the bottom of an ocean, unseen, unheard, and uncontrolled. They will get their execution. I will get my freedom.” Simon finds this sprawled into a note hidden away in the back of his submarine. The final words of a fellow prisoner, another victim of hopelessness at the bottom of an ocean of blood inside the Iron Lung.
Releasing Jan. 30 2026, Iron Lung is one of the largest indie movies of the past decade. The film is based on an indie video game of the same name, which was developed by the independent game developer David Szymanski. Iron Lung is a sci-fi horror film produced, directed, starred, and written by popular internet star Mark Fischbach, most commonly known and attributed as Markiplier. Markiplier plays Simon, a convict in part of a “conviction realization” program in which he is forced to explore a largely unknown ocean of blood in exchange for his freedom. The vessel in which he takes on this journey is a submarine known as the “Iron Lung,” a rusty ship being pushed far beyond its limits. This craft is where the entirety of the film takes place.
As one of the few major bottle films in recent cinema, several critics described the movie as overly slow and remarked the middle as “boring.” However, it was through this “slow” transition that Iron Lung is able to immerse you in the story; to question what’s real and what’s just another sign of Simon’s world collapsing in front of his very eyes.
The worldbuilding in Iron Lung leads to such interesting ideas that they’ll stick around in your head well after you’ve finished the movie– it makes you ponder so much about this world, even with such a small glimpse of it. The film uses a slow buildup of tension in order to maintain an atmosphere of mystery, fear and deliver an intense climax. The story isn’t just about scaring the viewer– rather, the story being told is one of human nature and learning to give up ideas of a “fair” and “happy” ending in order to face your past head-on for the greater future.
Editor’s note: Past this point there are references to many spoilers in the movie which may negatively impact your viewing of it if you have not watched it before, so I would highly recommend going to watch it and coming back if you found the first part of this review interesting! Additionally, this review will discuss several aspects which viewers may be sensitive to, such as death, claustrophobia, and horror.
The sub is completely designed to set the atmosphere of the film, and it does so perfectly. Aspects such as the idle background noises of the pipes, faint glows of the text displays and meters, and repeating positioning of shots as Simon navigates the Iron Lung from location to location all give the viewer a sense that although this world is unfamiliar and constantly shifting, Simon is not. Yes, he’s completely terrified of the ship and the things that are down there with him, but regardless he works systematically and efficiently because he cares about nothing more than his one main goal – survive, get out, and earn his freedom. Even when he knows the things out there are trying to kill him and he knows that they likely will, he goes back again to retrieve the black box data of a crashed ship because he’s told that’s how he’ll earn his freedom from this torment, and that’s how he’ll finally pay for his past. Because Simon wants to believe that the world is just. He wants to believe that after he’s “earned” his happy ending, after he’s “atoned” for his past, he’ll finally be able to find a satisfactory ending to his story. What our protagonist needs to learn is that the world isn’t truly fair.
When Simon is told that he needs to go back and retrieve the black box data, the reason he goes isn’t because he wants to save humanity. He doesn’t even really believe that it will, he’s purely driven by the idea that this is how he pays for his past and earns his freedom. Not just freedom from the Iron Lung and from his containment, but from himself. The reason Simon is a convict in the first place was because he was blamed for the destruction of Filament Station which resulted in killing several people. He persistently denies that he was to blame throughout nearly the entirety of the movie, yet we see over and over that deep down, he truly does blame himself. His one way of coping with this was the idea that after he had paid for his crimes down here, he would finally be able to return with this weight finally lifted from him. When he then learns that the sub meant to take him back up to safety had been destroyed, that his only way of getting out is gone, he loses all sense of hope and direction.
After Simon’s only reason to keep going was ripped right out from under him, it becomes unclear whether he’d continue on to retrieve the data at all; he had no reason to. That is, until he finds a new reason to keep going: the same beast that had been taunting him this entire time. Simon takes the insecurity of his past that the monster in the blood ocean had been using to control him, and uses it as a new fuel to keep going.
Iron Lung does a marvelous job of showing this transition, as Simon switches from being helplessly consumed into the blood ocean to instead taking control of himself and the submarine. Simon uses previous mockings of the monster such as calling him “Simon the butcher” and decides that if that’s what the monster sees of him, that’s what the monster will get. Iron Lung is able to show a complete transformation of Simon running away from his past and punishing himself for it, to instead now facing it head on. He realizes that instead of it being something for him to fear, it’s a part of him that can’t be ignored or pushed to the side. This psychological change is presented physically as he faces the monster head on in order to save the black box data – not as a way for him to pay for his past, but to accept it and be able to truly come to peace with it.
This film uses these elements perfectly in order to tell and display this story, which gives viewers an experience that is entertaining, satisfactory, and conclusive. Simon’s journey presents a message of learning to accept and embrace your past rather than hiding it, and shows that facing them is always better than running and hoping for them to go away on their own. Overall this film is one of the most promising to come out recently, as although it serves as its own self contained story rather than just pushing sequel bait for a quick cash grab, it still leaves lots of questions open. Not fully “unanswered,” but open enough for the viewer to be able to think about all the possibilities and implications of the world. Iron Lung is the type of movie that’s almost more fun to analyze and think of possible loose ends and implications than it is to watch for the first time. Whether that’s a positive or not depends on individual viewpoints and preferences, but regardless I can’t recommend the film highly enough.
Should you play Iron Lung (the video game) before watching Iron Lung (the movie)?
If you haven’t played the game and are wondering if it’s necessary to play it before watching the movie, the answer is… not really. The game is a low-poly indie horror game from 2022 with only about an hour of playtime and very basic gameplay of navigating the floor of the blood ocean. The main gameplay obviously contains the key concepts and some small references as are reflected in the movie, but the bulk of the plot isn’t nearly as in depth or complex as the movie goes into. However, the game does include a console interface in the back of the sub which allows you to search up and get information on specific terms and pieces of lore. This is the only real main story the game has, so while it provides some information, it is not necessary to play in order to enjoy the movie. However, if you’re interested in or are a big fan of the movie, I would recommend playing through it in order to explore concepts in the movie a bit more. The game is available on most platforms for a relatively low price, but if you can’t play it yourself or don’t want to purchase it you can also watch a playthrough of it. You can even watch Markiplier’s initial playthrough of it online before watching him star in the movie!
