Title: Iron Lung
Director: Markiplier
Studio: Markiplier Studios
Release Date: January 30th, 2026

Last week, Iron Lung became a surprise box office hit, grossing $30 million USD globally on a budget of only $3 million. That’s not the only unusual element of the movie. It’s a game adaption produced by and starring the YouTuber Markiplier. The reception has been mixed, with it receiving a paltry 59% critic score on Rotten Tomatoes, a 4/10 from IGN, and a mediocre 6.6/10 on IMDB. At the same time, the film has an 89% audience score on Rotten Tomatoes. Should you believe the critics, or the audience?

Premise

Hundreds of years from now, when humanity is a spacefaring civilization, an event called the quiet rapture happens. All of the stars and habitable planets in the universe disappear, leaving scant few survivors aboard space stations and ships. One of these survivors is Simon, a convict, played by Markiplier, and is the main actor in the film. He is welded into a metal submarine called the iron lung, and forced to explore an ominous moon covered in a sea of hot human blood. His only connection to the rest of humanity is a radio to communicate with the station that sent him down, and his only way to see outside his vessel is with an X-ray camera.

Simon must learn to handle the clunky technology of the submarine, navigate the seafloor and the creatures that inhabit it, and uncover the mystery behind the blood moon that may hold the key to the salvation of mankind.

Reaction

Iron Lung has a lot going for it as a film. Markiplier does a good job of playing Simon, in his mix of paranoia, guilt, terror, and desperation. His submarine is creepy, claustrophobic, feels like it was put together with scraps and could fall apart at any moment. The X-ray camera was the highlight for me: It gives us such a narrow, clinical view of that sea of viscera and its denizens. That, combined with the lack of exterior shots lets the mind wonder and fester on what lurks outside Simon’s tin can. While never seeing the exterior did wonders for the imagination, the submarine interior felt so uncomplicated and like the video game. Whether this was done out of fidelity to the game, or as a consequence of the limited budget, I’m not sure. But the simplicity of the submarine’s layout did harm my immersion, even when we got to see the guts of the vessel. Aside from that, the film’s small budget was hard to notice. Even the heaviest CGI and practical-effects filmed moments, the shots were never undermined by the thin wallet spent to make it.

Aside from the set design, Iron Lung has a few other flaws. The movie is what a fan might call a slow burn, or a critic might call sluggishly paced. In my opinion, the movie could have used about 15 minutes less of Simon trying to figure out the very simplistic controls of the vessel and navigating around the seafloor without anything happening. At a two-hour runtime, those scenes would not have been missed. Even so, the slower moments gave me time to examine the strange and clunky technology, as well as to speculate about the mystery behind the blood moon and the quiet rapture. The sound mixing, on the other hand, had some issues. While the ambient noises and soundtrack of the film were quite good, there were times where several voices would talk over each other, and I wasn’t able to understand any of them. I felt like I missed important story beats as a result.

Final Score (3.5/5 Stars)

Like much of the cosmic horror genre, Iron Lung filled me with a lot more dread than it did terror. Even at the moments of peak excitement, I reckoned that some of the previews before the movie scared me more than Iron Lung did. That’s not a knock against the film, for me at least. But for anyone who’s looking to be frightened has better options. For fans of Markiplier, the video game it’s based on, or indie films in general, Iron Lung is undoubtedly worth the watch. For everyone else, it depends on how much patience and love you have for Cosmic Horror and slow burn films. While I enjoyed the film throughout, this is not a movie that I will be rewatching anytime soon or thinking about in the future.

What about you? Did you enjoy Iron Lung? Are there other indie films, horror or otherwise, that should be on our radar? Let us know on the Boss Rush Discord.

Featured Image Credit: Markiplier Studios