Iron Lung, a 2022 indie horror game by David Szymanski, takes place in the future after the quiet rapture caused all stars and habitable planets in the universe to disappear, leaving only the people on space stations and star ships. To survive, one of the colonies launched a submarine on an expedition to a moon that recently formed a blood ocean, where it is believed to hold resources necessary to sustain life.
In the gameplay of “Iron Lung,” the player is a nameless convict piloting a submarine in the trenches of the blood ocean, taking pictures from a low-quality camera on the front of the submarine. While taking photos of fossils, a building, and a mysterious light, a variety of problems occur, like pipes bursting, fires starting, and equipment malfunctions. After taking the final photo at the end of the game, the submarine is crushed by a massive sea monster, where the screen abruptly turns black before fading into the title screen.
On May 19, 2022, Mark Fischbach, or better known by his online persona, Markiplier, released a YouTube gameplay video of “Iron lung,” Fischbach loved the game because of its intense claustrophobic atmosphere, as well as his general fascination with deep sea horror. He enjoyed the game so much that on April 21, 2023, he announced he wanted to make a film adaptation of “Iron Lung.”
About a year later, Szymanski made a joke on the social media app X explaining he was starring in a film adaptation of “Iron Lung.” The movie would be starring Fischbach and Sean Mcloughlin, better known as Jacksepticeye, another popular youtuber that was slated for a summer release. Szymanski later confirmed it wasn’t a joke and that it was intended to be released in theatres January 30, 2026.
The production of the movie started at Troublemaker Studios in April 2023 and ended on May 1. On April 29, 2023, Fischbach had officially finished filming and moved into postproduction.
Throughout the film, Fischbach was able to capture the motion of the submarine in a really creative way, by having the entire set on a robotic motion platform, often referred to as a gimbal. Since the whole set was on a gimbal, it allowed the submarine to shake, tilt, and yaw, making the set feel like a real submarine from the inside, making the movie even more impressive despite the budget of 3 million dollars.
On Dec. 7, 2025, Fischbach revealed on a live stream the precise amount of fake blood used for the movie was 80,000 gallons, which is impressive because it beat the previous record of 50 to 70 thousand gallons held by the “Evil Dead” remake. All of the fake blood made working inside of the set hard to work in, eventually leading to Fischbach getting hurt by too much fake blood in his eyes and sending him to the hospital.
In December, Fischbach published the release date trailer and opening ticket presales. The movie was only meant to be released in 60 theatres, but Fischbach encouraged his fans to request it directly from theatres near them, leading to the movie to be shown in 1500+ theatres. After the release of the movie, some of the theatres partnered with hospitals and encouraged movie goers to donate blood, leading to 37,000 donations.
The plot of the movie is a lot like the game’s plot, except for some things Fischbach added. In the movie, the main character, Simon, a convict involved in the destruction of a space station, pilots a small submarine named the SM-13 on a planet that’s mostly made up of an ocean of blood. Simon is tasked with taking pictures of things in the ocean, but while he’s doing this, he goes through several struggles like hallucinating, equipment problems, and blood from outside leaking into the sub.
While the movie is almost an exact replica of the game, Fischbach did do some things differently by giving the lore a new, better ending. In the game it ends with the player being crushed and taken to the title screen, so players are left wondering what happened to all of the information they gathered throughout the exploration. However, the movie is different, as Simon sabotages the submarine before getting crushed by a sea monster, showing the black box with all the data gathered floating on a life vest on the surface of the blood ocean.
Overall, the movie is surprisingly accurate to the game, mimicking the submarine almost perfectly and keeping the claustrophobic and eerie feel the game has. I suggest this movie to anyone who enjoys science fiction horror movies or specifically science fiction deep sea horror. The movie has a perfect blend of tension, horror, and creativity that perfectly brings the game to life.
