If The Mean Greens - Plastic Warfare generated the same gross revenue on the Epic Games Store, Virtual Basement LLC, Code Headquarters LLC would keep approximately $2,652,075 - that's $637,924 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $225,283. 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 $2,014,150.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.