The gap between a video game and its cinematic adaptation is often wide, but few attempts bridge it with such personal stakes. When YouTuber Markiplier (Mark Fischbach) took on Iron Lung—a first-person horror sim where players navigate a blood-filled alien ocean in a cramped submarine—he didn’t just play it. He directed, produced, and starred in a 2.5-hour film adaptation, a rare case of a creator turning their own gameplay into a feature-length experience.
For fans of the game, the choice is clear: Should they revisit the 45-minute YouTube playthrough or dive into the movie? The answer isn’t as simple as it seems.
What Iron Lung* does best
The game thrives on tension through restraint. Players control a windowless sub, relying on minimalist controls to steer through an ocean of blood while photographing unseen horrors. The absence of dialogue, combined with eerie sound design and slow, deliberate movement, makes every second feel like an exercise in controlled panic. Markiplier’s YouTube playthrough captures this perfectly—his reactions to the game’s unsettling discoveries are genuine, and the pacing mirrors the game’s deliberate dread.
The movie, however, struggles to replicate that precision. Early scenes—like the moment Simon, the protagonist, surfaces briefly to plead with his handlers before being sent back into the abyss—retain the game’s oppressive atmosphere. The sub’s interior is meticulously recreated, with hidden compartments and subtle details that deepen its sense of isolation. But the film’s second act abandons subtlety, drowning in screaming, distorted intercom chatter, and over-the-top sound effects that turn dread into chaos.
Where the movie falls short
Expanding the game’s lore into dialogue is a risky move, and the film doesn’t always land it. Terminal entries from the game—revealing fragments of the sub’s dark history—are reimagined as frantic, half-heard transmissions. The result? Critical information gets lost in the noise, and what should feel like discovery instead becomes a slog. The movie’s biggest flaw isn’t its ambition but its inability to match the game’s minimalist horror with restraint.
A love letter with flaws
Despite its missteps, the film has heart. Markiplier’s attachment to Iron Lung—a game he played in a single sitting—is palpable. The sub’s claustrophobic design, the slow drip of blood on its porthole, and the creeping sense of something wrong in the depths are all faithfully preserved. It’s a labor of love, even if it doesn’t always work as intended.
For those who prefer their horror in short, immersive bursts, the game remains the stronger experience. But for fans of Markiplier’s creativity, the movie offers a flawed but fascinating experiment in adaptation.
Final verdict: Play the game.
Iron Lung* is available for $4 on Steam, making it the smarter—and scarier—choice.
