With Iron Lung, YouTuber Markiplier, real name Mark Fischbach, becomes the latest content creator to dip his toe into the world of feature film production. His effort is not as accomplished as the work of the Philippou Brothers (creators of Talk to Me and Bring Her Back) but it's a lot more striking and original than last year's Shelby Oaks (directed by YouTube film critic Chris Stuckmann). The film is based on a relatively niche video game of the same name, which was made by solo developer David Szymanski (who helped with the film's screenplay) and is set inside a submarine exploring an ocean of blood. We follow exactly the same premise here as our protagonist, a convict named Simon, spends the entire runtime welded into a decrepit submersible on a distant moon trying to earn his freedom. What his superiors are specifically looking for is unclear but he is told the blood ocean holds resources vital to the survival of mankind, who has been pushed to the brink of extinctio...