‘Iron Lung’ Sinks You Into Cosmic Dread But Wearily Bobs Along

Based on David Szymanski‘s 2022 indie horror game, Mark Fischbach’s Iron Lung is a grim, claustrophobic descent that values atmosphere over momentum.

Set after ‘The Quiet Rapture’, a cosmic event where millions of people and entire stars vanished overnight (or so a bone rattling voice-over tells us), the film quite literally drops us into humanity’s last chance of survival: an ocean of blood on a barren moon.

In a universe ruled by fear, Simon, a convicted criminal played by Fischbach (aka Markiplier), is forced by the Consolidation of Iron to pilot the titular submarine through the red depths, in exchange for his freedom.

Soon, Simon descends into darkness, trapped alone and stalked by something unseen.

The film hooks immediately, leaning into mystery with confidence: eerie voice over, cryptic worldbuilding, and a sense of dread that feels immediate.

Markiplier carries the film as best he can solo, throwing himself fully into the role. Watching him spiral inside the metal coffin is often compelling, really buying into his rage and desperation, especially as isolation turns into hallucination.

But the role also exposes the film’s limits. While the performance is intense, it often feels repetitive. But even when the narrative stalls, his commitment never feels half-hearted and it’s still entertaining to watch Simon endure all the horrors.

The supporting cast (Caroline Kaplan, Troy Baker, Elle LaMont) exists mostly through voiceovers, adding texture, unease and unintended cheese, but Elsie Lovelock  defiantly stands out as the haunting presence that stalks Simon.

Visually, the film impresses, especially for a low budget. The single submarine set into feels tactile though its limits are eventually made clear.

Practical effects are always a welcome delight, and Iron Lung delivers with stomach-turning detail, from blistered skin to buckets of congealed blood.

The VFX, particularly one trippy sequence, and cinematography find striking compositions inside the tight space until the effect wears thin. 

Even the monsters, though desperately underutilised, leave an impression as horrific, razor-toothed Eldritch goo.

Despite its effort, the film struggles, especially with pacing. It lingers where it should move and rushes through tense moments that need space, creating a blatantly uneven rhythm that slogs.

At two hours, the runtime becomes a weight that the story can’t support. What works in a tightly designed game doesn’t always translate to feature length and the stretch shows here.

The slow burn undoubtedly builds mood but never quite delivers a pay off that its patience demands, while the narrative circles emotional beats without deepening.

Surprising with flashes of humour, it’s also not very scary though the third act delivers a chaotic bloody finale rivalling Evil Dead. 

There is craft and clear ambition here. Fischbach’s passion for the world, tone and experience shows in the film’s atmosphere and design.

As an indie project, it’s memorable and often immersive, but tighter editing and sharper focus could have made it something great.

Iron Lung will land for audiences who love slow-burn horror and cosmic dread, especially fans of the YouTuber himself. For others, it may feel as trapping as the story portrayed rather than gripping.

Brimming with Lovecraftian energy, the film offers rare dive in modern horror that’s held back by its narrative slack and uneven pacing.

★★½

Iron Lung is in cinemas now.