If Hero's Adventure: Road to Passion generated the same gross revenue on the Epic Games Store, 半瓶醋工作室(Half Amateur Studio) would keep approximately $8,620,066 - that's $1,858,650 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $1,039,100. 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 $6,761,416.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.