The stars have gone out. The planets have disappeared. All that remains after “The Quiet Rapture” are dark moons — and the remnants of humanity clinging to existence on the few surviving starships and space stations. Desperate for answers, the crew of a ship welds a convicted criminal into a submarine and drops him into an ocean of blood on a desolate moon to search for resources or answers that could save humanity.
Written, directed, edited, and staring Markiplier (Mark Fishbach), Iron Lung is an adaptation of the horror video game created by David Szymanski, in which the player is must explore a blood ocean using nothing but coordinates, an impact warning system, and a camera that only captures grainy black and white images of what lies beyond the iron walls of the submarine.
Much like the game, the movie begins with the confines of the submarine and remains so throughout the two hour runtime. We witness the universe from Simon's (played by Markiplier) cramped perspective inside the vessel. He has little control over his world, only able to steer the boat by following the indicated coordinates and then capturing images of the floor of the blood ocean.
The camera work and editing do a lot of heavy lifting in maintaining a feeling of tight claustrophobia and keeping Simons movements through this small space visually interesting. The sound design is also excellent, with the groans and thuds of the metal adding to the unease of being trapped and unable to see what's lurking beyond sub. The only time we get a glimpse of the outside world and other people is when the sub is briefly raised to the surface — and even then, we only get a blurry, blood-smeared view of the what lies beyond a small porthole, holding true to the feeling of being trapped in a tight space.
As the blood ocean offers up its terrifying secrets little by little, Simon is forced to confront his past crimes and his continued desire for freedom and life above all. Fishbach gives a solid performance, evoking Simon's growing frustration, despair, and hopelessness as the dangers begin to flood the tiny world of this submarine.
Iron Lung is not a perfect movie. Some of the early sections drag and could have been tightened up a bit. Some of the writing could have received a bit more polish. But for me, these are small quibbles in a wonderfully weird experience that grows more and more intense and unsettling as the movie builds up the layers of its bizarre cosmic horror. I genuinely enjoyed seeing it in theaters and will likely watch it again.
A Win for Indie Filmmaking
Since its theatrical release, Iron Lung has become a notable success despite having no studio or distributor. The film, which was reportedly produced for around $3 million, has been shown in more than 3,000 theaters across the U.S. and grossed $37.9 million domestic ($44 million worldwide), according Box Office Mojo (as of February 17, 2026).
Many critics and indie filmmakers have heralded this success as a sign of a shift in the industry, opening the door for more indie projects to be produced and make it into theaters. However, it should be noted that Markiplier has a massive fanbase (with 38.3 million subscribers on YouTube), who are ready to mobilize in fervent support for his various projects. In 2019, as just one example, he released his "Tasteful Nudes" calendar and raised $500,000 in just two days for the Cancer Research Institute.
In the same way, Markiplier was able to rally his fanbase in support of Iron Lung., as fans were instructed to call their local theaters and request a showing of the film, resulting in a high number of preorder ticket sales. This, combined with offering theaters a 50/50 split on ticket sales, made it viable for more theaters to take a risk on a smaller project.
Furthermore, due to Markiplier's immense success as a YouTuber, he has stated in the past that he has "unfathomable" amounts of money. This financial stability provides him the freedom to experiment with odd projects like this, which he can then fund and distribute himself.
So, will indie filmmakers benefit from Iron Lung's success with more opportunities to get their work produced and shown in theaters? It remains to be seen.
Iron Lung could just be an outlier. However, it's success is a significant achievement. It shows that audiences are willing to support creators they respect, and they are willing to turn out in theaters for unique indie film experiences. I genuinely hope this inspires more investment in odd, little indie films. I would love to see a resurgence of wonderfully, weird and experimental filmmaking powered by indie creators, similar to what we saw in the '90s with such tiny-budgeted films like Clerks, El Mariachi, Run Lola Run, Pi, The Blaire Witch Project, Welcome to the Dollhouse.
An Influx of Indie Horror Game Adaptations
Iron Lung is also a part of a larger trend I’ve noticed in recent years, in which indie horror games have been receiving film adaptations. One of the most well-known examples is Five Nights at Freddy's. The game was originally created by Scott Cawthon in 2014 and then grew into a huge franchise franchise with numerous games and spinoffs, as well as novels and a major motion picture from Universal Pictures in 2023 and a sequel in 2025 (earning $291.5. and $238.3 million worldwide, respectively).
The Exit 8, a minimalist horror game developed by Kotake Create, in which the player is trapped in an endlessly repeating metro hallway, was adapted into a Japanese live-action film. Since its international release across various countries in 2025, the movie has already earned $39.1 million worldwide (as of February 17, 2026). Its U.S. release is coming in April 2026.
The Mortuary Assistant, a psychological horror game developed by DarkStone Digital in 2022, was adapted into a film that will soon be released on March 27, 2026. The story follows a young mortuary graduate, who takes her first job at a mortuary — only to realize the bodies possessed by demons and to survive the night she must discover the demon’s name or risk becoming possessed herself. In the game, this involves solving puzzles while continuing the embalming process.
Other indie games reportedly being adapted to film include Vampire Survivors (developed by Luca Galante), Poppy’s Playtime (developed by Mob Entertainment), Outlast (developed by Red Barrels), The Medium (developed by Bloober Team), Dredge (developed by Black Salt Games), and Bendy and the Ink Machine (developed by Joey Drew Studios). And I wouldn’t be surprised if there were others I haven’t discovered yet.
Indie horror games are a fantastic source for adaptation. With their (often) unique monsters and conceptual design, as well as their tendency to take place in a single or small number of locations, indie games often align with the requirements for low-budget indie filmmaking. In addition, indie horror games can sometimes achieve viral moments, with let’s players and streamers sharing the spooks with their fans, bringing it to a wider audience.
Another element is the accessibility of approaching an adaptation as a filmmaker. Major video game franchises — such as Fallout (Bethesda) and The Last of Us (Naughty Dog) — are owned by huge corporations, which creates a lot of red tape and financial investment t0 get a film adaptation off the ground.
Smaller, indie games, however, may have been created by a single developer or a small team, who are often excited to just having their game played and noticed, let alone having the opportunity to see it adapted into a movie. It’s a perfect opportunity for one indie creator to connect with another indie creator and expand the world into a new narrative format. And I wouldn’t be surprised if we continued to see these kinds of adaptations in the near future, especially following the success of Iron Lung.
Iron Lung – Official Trailer
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