As threatened, the Steam Next Fest June 2025 is now underway, offering a week of presentations, sales, and time limited demos. The Official Trailer acknowledges the enormity of this flood of content Valve is launching amid a flood of content. This post has more. Here's a bit:

We host Next Fest three times a year (February, June, October) as a way to give developers from around the world a captive audience for their demos on games they haven't released yet. If you already have a bunch of genres that are your faves, feel free to search that way. BUT we also encourage you to try something new-- check out the video player at the top of the main Next Fest hub for a new sprinkling of demos each day and perhaps discover your NEW favorite genre or theme!

Several developers are hosting livestreams as well, so be sure to check those out. Play free demos all week, and wishlist your favorites so you can be notified when the full game officially launches at a later date!