If NARUTO: Ultimate Ninja STORM generated the same gross revenue on the Epic Games Store, CyberConnect2 Co. Ltd. would keep approximately $3,117,987 - that's $733,225 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $288,816. 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 $2,384,762.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.