How many copies did Mythgard sell?

An estimated 36k to 58k copies, based on its 1k Steam reviews. This is a labeled estimate from the review count, not exact sales.

How much revenue did Mythgard make?

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

How big is Mythgard?

Estimated owners: ≈ 36k–58k; from 1k reviews (Very Positive)

A labeled estimate from the public review count (adjusted for release year), not exact sales. Owner data cross-checked with SteamSpy.

Does this actually work?

We left Mythgard out and predicted the genre from its 8 similar games. Every figure here, including Mythgard's, is estimated from Steam reviews, not self-reported sales.

Copies, estimated from reviews

typical (middle half) 1.6M–2.5M

best case 8.2M (Slay the Spire)

The Card Game lane

A big, proven genre, though hit-driven: most sell around 2.0M copies, while a few break out far above.

A typical game

≈ 2.0M copies

≈ $9.4M after Steam's cut

from ~49k reviews

Best case

≈ 8.2M copies

Slay the Spire · ≈ $78.8M after Steam's cut

from 216k reviews

A breakout hit, far above a typical game.

7 of your 8 games sit in the typical range; 1 is a breakout hit far above it.

Copies and revenue are rough lifetime estimates from the review count; typical figures are medians per column, so they can come from different games.

The lane you'd be entering

Winners here lead with Roguelike Deckbuilder + Card Game, priced around $25.
The breakout hits carry Roguelike Deckbuilder + Rogue-like + Card Battler; a typical game here doesn't.
None of the games you compared shipped in the last two years; the newest is from 2020. That says more about your picks than about the market, so add newer similar games to read the timing.
A typical game here lands in Diamond ($1M+ before Steam's cut, est.). Tiers: Chris Zukowski's benchmark tiers.

Similar games

Game	Price	Reviews	Tags	Est. copies	Est. revenue
Dota Underlords 2019	Est. copies ≈ 2.6M–4.3M 1.8x vs typical SteamSpy 5M–10M	Est. revenue Free	Free	91k reviews Very Positive	Free to PlayStrategy +6
Magic Duels 2015	Est. copies ≈ 1.1M–1.8M SteamSpy 2M–5M	Est. revenue Free	Free	24k reviews Mostly Positive	Free to PlayCard Game +6
KARDS - The WW2 Card Game 2020	Est. copies ≈ 1.3M–2.1M SteamSpy 2M–5M	Est. revenue Free	Free	49k reviews Mixed	Free to PlayCard Game +6
GWENT: The Witcher Card Game 2020	Est. copies ≈ 728k–1.2M SteamSpy 1M–2M	Est. revenue Free	Free	28k reviews Very Positive	Free to PlayStrategy +6
Minion Masters 2019	Est. copies ≈ 1.9M–3.1M SteamSpy 500k–1M	Est. revenue Free	Free	65k reviews Very Positive	PvETrading Card Game +6
Slay the Spire 2019	Est. copies ≈ 6.2M–10.1M 4.4x vs typical SteamSpy 5M–10M	Est. revenue $42.7M–$114.9M net $77.7M–$176.7M gross	$24.99	216k reviews Overwhelmingly Positive	Roguelike DeckbuilderCard Game +6
Yu-Gi-Oh! Duel Links 2017	Est. copies ≈ 1.5M–2.5M SteamSpy 2M–5M	Est. revenue Free	Free	45k reviews Very Positive	Free to PlayCard Game +6
UNO 2017	Est. copies ≈ 1.9M–3.0M SteamSpy 2M–5M	Est. revenue $5.1M–$13.7M net $9.3M–$21.1M gross	$9.99	54k reviews Mostly Positive	Card GameMultiplayer +6