Steam Next Fest is a week-long celebration featuring hundreds of FREE playable demos as well as developer livestreams and chats. Players try out upcoming games on Steam pre-release, developers gather feedback and build an audience ahead of their Steam launch, everyone wins!
Depends on your tastes. I for my part love strategy and RPGs, so I'm trying the demos of Broken Roads (RPG set in rural australia after some kind of apocalypse, inspired by the first two fallouts) Gord (Base building in a dark fantasy world with emphasis in the sanity of your people) Shadow Gambit (tactics game inspired by commandos and desperados, from mimimi, creators of blades of the shogun and desperados 3) New Cycle (city builder after a solar flare has wiped out civilization) Laysara (city builder in the slopes of a mountain)
At the moment I've tried the first two, and they aren't bad but also nothing to write home about, shadow gambit I have a lot of hype for it, their first two games are superb. And the last two are games that I stumbled upon now and look good, we'll see.
I'm not into Celeste, platformers, or things that require actual skill. But if you are, my husband spent a good hour or so enjoyably raging at Memori last night.