Mark Fischbach, better known online as “Markiplier”, self-financed his indie film adaptation “Iron Lung”, which he produced, wrote, directed, and starred in. As a slow-burning sci-fi horror film, it relies on tension and atmosphere rather than jump scares. The film delivers an uneasy experience by trapping both its main character and the audience in a confined environment.

Set in a post-apocalyptic future, the story’s main character is a convict sent on a mission to explore an ocean of blood discovered on a distant, lifeless moon. The only way to explore it is through a small, rusty submarine known as the Iron Lung. With no exit access points, limited instruments, and a welded shut hatch, the mission quickly becomes a psychological test of fear and isolation for the convict.

One of the film’s strongest factors is its sound design. The constant creaking of the sub, distorted voice lines, and unexplained eerie noises outside of the submarine create a sense of uneasiness that lingers through the film. Even during quieter moments, the film maintains its tension, making viewers feel as if something could go wrong at any time. This approach proves effective, especially for audiences who appreciate subtle horror.

Visually, “Iron Lung” is dark and claustrophobic. Using 80,000 liters of fake blood, it beat the previous record of 50,000 to 70,000 liters of fake blood used in a film by a good margin. The limited number of clear visuals forces the audience to imagine what could be lurking outside the submarine’s walls, adding to the overall fear. The film utilizes various camera angles that capture the scene in a unique fashion, and it also adds to that sense of being trapped in a confined space. Fischbach is visible on screen for most of the film, delivering a believable performance that captures fear, frustration, and desperation as the mission goes on.

The film may not appeal to everyone. Viewers expecting a fast-paced horror movie with frequent action, unexpected jump scares, or both, crystal clear dialogue, and explanations may find the pacing quite slow. The film leaves many questions unanswered, choosing uncertainty over resolution. While this choice strengthens the atmospheric aspect, it may leave some audience members frustrated.

Overall, “Iron Lung” succeeds as an atmospheric sci-fi horror film. Demonstrating that fear comes from what remains unseen and not just what is shown on screen, fans of psychological and sci-fi horror should add the movie to their watchlist.