If Freeman: Guerrilla Warfare generated the same gross revenue on the Epic Games Store, KK Game Studio would keep approximately $7,614,956 - that's $1,653,059 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $902,039. 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 $5,961,897.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.