Serene puzzle adventure Rime (opens in new tab) is the latest Epic Games Store freebie, available between now and May 30. It'll be followed by the Arabian Nights-themed City of Brass (opens in new tab).
Rime's a lovely puzzler with shades of Ico and Zelda. You're stuck on a large but mostly deserted island full of picturesque ruins and lots of things to climb. Puzzles run the gamut from simply moving objects around to mucking about with light, sound and perspective. It's clever, but the puzzles shouldn't stump you, and you've conveniently got a fox pal to offer some subtle guidance.
City of Brass I'm less familiar with, but I know you get a whip (opens in new tab)! Not enough whips going around in videogames. This first-person whipper will task you with exploring a magical metropolis, beating up and trapping monsters as you fight to its centre.
For the Epic Games Mega Sale, the freebies have been bumped up to one a week. Stories Untold, which was released during the regular fortnightly freebie period, still has another week left. I confirmed with Epic that, for the rest of the sale, the games will stop being free after a week.