How many copies did Spiral Knights sell?

1.5M to 2.5M copies, based on its 24k Steam reviews. This is a labeled estimate from the review count, not exact sales.

How much revenue did Spiral Knights make?

Spiral Knights is free to play, so there is no copy-sales revenue to estimate.

How big is Spiral Knights?

Estimated players who have it: ≈ 1.5M–2.5M; from 24k reviews (Very Positive)

Copies are estimated from the public review count, adjusted for release year, and cross-checked against SteamSpy's own estimate.

Did the prediction match what actually happened?

We hid Spiral Knights and predicted how it would do from its 8 similar games. Every figure here, including Spiral Knights's, is estimated from Steam reviews.

Copies, estimated from reviews

typical (middle half) 4.7M–12.8M

best case 33.8M (The Binding of Isaac: Rebirth)

Games like Spiral Knights

A typical game among these

≈ 4.7M–12.8M copies

≈ $34.7M–$91.7M after Steam's cut

from ~195k reviews

Only the top fifth of 2019's Steam releases earned $34k or more before Steam's cut, so plan for that or less.

All 8 of the similar games are hits.

Best case: The Binding of Isaac: Rebirth at ≈ 25.8M–41.9M copies, ≈ $106.2M–$285.5M after Steam's cut.

What their first month looked like

About half the games that made it here had over 33k reviews in their first month; the range was 17k to 102k.

The genre you'd be entering

These games: The similar games share Dungeon Crawler (6 of 8) and Rogue-like (5 of 8).
The winners: Winners here lead with Action Roguelike + Rogue-like, priced around $15.
When they shipped: The similar games span 2013 to 2024, and 1 of the 8 shipped in the last two years.

How these numbers were worked out

A hit here: 1,000+ reviews, roughly $150k+ before Steam's cut (a standard indie benchmark).

Copies come from each game's reviews times a sales-per-review rate that falls with release age, from about 31 for the most recent game here to about 79 for the oldest, then widened into a range; revenue rides on that estimate times price. Source: GameDiscoverCo (2020) and VG Insights (2021).

Similar games

Game	Est. copies	Est. revenue	Price	Reviews	Tags
Cult of the Lamb 2022	Est. copies ≈ 3.2M–5.2M SteamSpy 2M–5M	Est. revenue $22.2M–$59.6M after Steam's cut $40.3M–$91.7M before Steam's cut	$24.99	130k reviews Overwhelmingly Positive	Base-BuildingCute
Noita 2020	Est. copies ≈ 2.2M–3.6M SteamSpy 2M–5M	Est. revenue $12.1M–$32.6M after Steam's cut $22.0M–$50.2M before Steam's cut	$19.99	89k reviews Overwhelmingly Positive	PhysicsRogue-like
Path of Exile 2013	Est. copies ≈ 15.8M–25.7M SteamSpy 20M–50M	Est. revenue Free	Free	250k reviews Very Positive	Free to PlayDark Fantasy
Enter the Gungeon 2016	Est. copies ≈ 3.7M–6.1M SteamSpy 2M–5M	Est. revenue $15.4M–$41.5M after Steam's cut $28.1M–$63.9M before Steam's cut	$14.99	90k reviews Overwhelmingly Positive	Bullet HellAction Roguelike
Darkest Dungeon® 2016	Est. copies ≈ 6.8M–11.0M SteamSpy 2M–5M	Est. revenue $46.5M–$125.1M after Steam's cut $84.6M–$192.5M before Steam's cut	$24.99	163k reviews Very Positive	Turn-Based CombatDark Fantasy
Hades 2020	Est. copies ≈ 7.7M–12.5M 1.6x vs typical SteamSpy 5M–10M	Est. revenue $52.9M–$142.2M after Steam's cut $96.1M–$218.7M before Steam's cut	$24.99	310k reviews Overwhelmingly Positive	Action RoguelikeRogue-lite
The Binding of Isaac: Rebirth 2014	Est. copies ≈ 25.8M–41.9M 2.4x vs typical SteamSpy 5M–10M	Est. revenue $106.2M–$285.5M after Steam's cut $193.0M–$439.2M before Steam's cut	$14.99	460k reviews Overwhelmingly Positive	Action RoguelikeRogue-like
Path of Exile 2 2024	Est. copies ≈ 5.6M–9.1M SteamSpy 20M–50M	Est. revenue $46.4M–$124.6M after Steam's cut $84.3M–$191.7M before Steam's cut	$29.99	227k reviews Mostly Positive	Action RPGHack and Slash