Usually Epic Store releases one free game a week under their weekly free game promotion. Next week, July 25, Epic will release two free games at the same time. These games are Moonlighter—which, incidentally, was part of the July Humble Monthly Bundle— and This War of Mine.
This is kinda funny since I decided to give the humble bundle a skip last month even though I thought Moonlighter looked interesting. Now its free on Epic even if it loads wacky for me.