What 2026 cosmic horror film, based on a video game and directed by Markiplier, is set entirely within a small, claustrophobic submarine in an ocean of blood on an alien moon?

The 2026 cosmic horror film described is "Iron Lung (Review)," an independent production written, edited, and directed by popular YouTuber Mark "Markiplier" Fischbach. This cinematic adaptation brings to life the 2022 video game of the same name by David Szymanski, immersing viewers in a truly unsettling premise. The story unfolds in a grim future following an unexplained cataclysm known as the "Quiet Rapture," an event that caused all stars and planets, along with most of humanity, to vanish without a trace.

In this desolate post-apocalyptic setting, Markiplier himself stars as Simon, a convict tasked with a perilous mission. He is forced to navigate a decrepit, tiny submarine, aptly nicknamed the "Iron Lung," through an expansive ocean of blood found on an alien moon. The film's intense claustrophobia is a key element, as the entire narrative is confined within the cramped, barely functional submarine, with the protagonist's only view of the outside world often limited to still images captured by an X-ray camera. This design choice amplifies the horror, preying on fears of the unknown and isolation.

"Iron Lung" gained significant attention not only for its unique concept and Markiplier's directorial debut but also for breaking a surprising record. The production utilized an astonishing amount of fake blood, exceeding 80,000 US gallons, setting a new world record for a horror film. Markiplier, known for his extensive gaming content on YouTube, particularly his playthroughs of horror titles, self-financed and self-released the film, marking a notable venture for a digital creator into mainstream cinema. The film delves into profound themes such as trauma, the will to survive, and survivor (Review)'s guilt, making it a thought-provoking experience beyond its visceral horror.