Most digital game stores typically keep 30 percent of revenue, though Steam just updated its policy -- it takes 30 percent of the first $10 million in sales, 25 percent of the next $40 million and 20 percent of anything over $50 million. Those changes won't affect the vast majority of developers, of course. Itch.io, meanwhile, doesn't take a set revenue cut, and developers decide what the split should be (that platform is mostly for indie and small-scale developers.)

Epic's store is opening soon on PC and Mac with a curated selection of games. It will add more titles and arrive on additional platforms over the next year. While developers can use any engine for their games, those who opt for Epic's Unreal won't pay engine royalties on the revenue they make through the store. Epic will also connect developers with 10,000 Twitch streamers, YouTubers and other creators through the Support-a-Creator program. The creators can earn rewards for bringing exposure to games.