If Knowledge, or know Lady generated the same gross revenue on the Epic Games Store, 蒸汽满满工作室 would keep approximately $1,406,648 - that's $383,178 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $55,452. Epic charges 0% on the first $1 million in annual per-app revenue and then 12% on the remaining amount. On GOG (30% cut), the developer would earn approximately $1,023,470.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.