If Hand of Fate 2 generated the same gross revenue on the Epic Games Store, Defiant Development would keep approximately $4,023,351 - that's $918,413 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $412,275. 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 $3,104,938.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.