# Iron Lung

> ResidualPlay case file: an overlooked Steam game still earning residual revenue. Estimates carry a ±30-50% error range per title.

- Steam appid: 1846170
- Developer: David Szymanski
- Released: 2022 · Genre: Adventure · List price: $7.99
- Deal grade: A (A = dormant with >=$5k/mo opportunity, D = low signal)
- Est. net residual revenue: $12.6k to $18.9k per month (mid $15.8k)
- Opportunity score: $20.5k/month at x1.30 dormancy multiplier
- Est. lifetime owners: 322.1k · Est. lifetime net revenue: $641.7k
- Review sentiment: 92% positive across 11156 reviews (10066 from Steam purchases)
- Review velocity: 316.5 reviews/month (6-month average)

## Why it's flagged

- Developer active, last post 5 months ago
- Studio active elsewhere (10 titles tracked), so this one may welcome a partner
- Last build shipped 34 months ago
- Store page localized in only 1 language(s)
- Last discounted 0 months ago, 9 sales in the last 12 months
- Proven demand elasticity: x5.4 review velocity during past deep sales

## Where a gross dollar goes (monthly, at current velocity)

| Stage | USD/month |
|---|---|
| Gross storefront sales | $28.6k |
| After VAT / sales tax (-13% blended) | $24.9k |
| After refunds (-9.5% median) | $22.5k |
| Net to developer (after Steam 30%) | $15.8k |

## Monthly review counts, oldest to newest (24 months)

57, 38, 60, 61, 87, 61, 44, 56, 39, 56, 34, 52, 49, 26, 57, 54, 183, 309, 1106, 262, 95, 144, 159, 133

## Missed seasonal-sale revenue (modeled)

Skipped 4 Steam seasonal sale window(s) in the last 24 months. Running a -50% discount in those windows is modeled at +$39.0k net in total, assuming a unit uplift of x5.4 taken from this game's own sale history. Same ±30-50% error range applies.

## Estimated acquisition range

$378.3k to $756.6k (2-4x the trailing net annuity of $189.2k/year). Same error range applies.

## Markets by review language

- japanese: 0% (game NOT localized in this language)
- schinese: 1% (game NOT localized in this language)
- brazilian: 2% (game NOT localized in this language)
- german: 1% (game NOT localized in this language)
- english: 88% (game NOT localized in this language)
- koreana: 0% (game NOT localized in this language)
- russian: 3% (game NOT localized in this language)
- french: 1% (game NOT localized in this language)
- spanish: 3% (game NOT localized in this language)

Localization gap: 100% of measured reviews are written in languages the game does not support (top: english). Localizing is likely immediate market expansion.

## Analyst notes (AI-assisted)

A 1-hour atmospheric horror game where you pilot a submarine through a dark lake using only radar and a map, uncovering an unsettling story through exploration.

Iron Lung has shipped 322k units lifetime for $642k net revenue with a 92% positive rating and still earns $15.7k/mo residual. The single-developer title punches well above its modest scope, driven by atmosphere rather than mechanics, and gained significant visibility after Markiplier's 2024 feature film adaptation. For acquirers, this represents a proven IP anchor with immediate film-to-game cross-promotion potential; for publishers, a revival window exists via console ports, expanded localization (currently English-only), and bundling with the Markiplier film. Risk is execution simplicity and short runtime limiting replayability without substantial expansion.

- Most realistic play: publishing
- Risk (market): 1-hour runtime and minimal replay value constrain upsell and retention; price sensitivity evident in reviews citing sale expectations despite 92% approval.
- Risk (tech): Developer last posted 5 months ago; solo-creator studio with 7 titles total may lack capacity for ports, live support, or sequel development without partnership.
- Risk (other): Film adaptation (Markiplier) may have cannibalized or frontloaded peak awareness; momentum window for expansion is now.

What players are asking for:
- More gameplay variety and content length without overstaying welcome
- Console ports (macOS workaround noted by player)
- Cosmetic or story expansions; sequel or expanded universe exploration

Suggested first moves:
1. Secure publishing rights and explore console versions (Switch, PlayStation, Xbox); film-game bundle on console storefronts capitalizes on Markiplier's audience crossover.
2. Localize into top-review languages (Russian 294 reviews, Spanish 326, Brazilian Portuguese 236) and negotiate Steam regional pricing; 100% loc gap suggests $2k-5k/mo upside.
3. Evaluate DLC or prequel/sequel with same universe; 316 reviews/mo and 92% sentiment create goodwill for episodic or expanded narrative content that respects 1-hour core experience.

Generated 2026-08-20 from public signals and player reviews. Directional, not diligence.

## Methodology

Units are estimated from Steam-purchase reviews times a release-cohort multiplier (Boxleiter method, 20-75x by year). Revenue uses an effective price (lifetime discounts and regional pricing) and nets out VAT (~13%), refunds (~9.5%) and Steam's 30% cut: roughly 55% of gross reaches the developer.

Source: https://residualplay.com/game/1846170
Citation: please cite ResidualPlay (https://residualplay.com) when using these estimates.