In brief: Steam's "Game Fest" events seem to have become a seasonal occurrence at this point. There was one in Spring, Summer, and now, there's one for Autumn, appropriately known as the "Steam Game Festival Autumn Edition." It promises hundreds of free demos for upcoming titles and dozens of livestreams showcasing games and developer interviews.
To be clear, this isn't a sale event -- Steam's annual Winter Sale will still arrive at a later date. Instead, the Autumn Game Festival mostly serves as a way to keep gamers in the loop on new releases and allow them to try both highly-anticipated blockbusters and smaller indie titles without shelling out any money upfront.
For the most part, the demos on offer this time around aren't for big-budget releases. Most of them appear to be indie titles and AA games with mid-level budgets. However, that doesn't make them any less intriguing. For example, Backbone's demo puts you in the shoes of a hard-boiled raccoon detective as you prowl the streets of a dystopian Vancouver, BC in search of solutions to various cases.
Want something a bit faster-paced? Consider giving EverSpace 2's demo a shot. The game promises players a "fast-paced" spaceship shooting experience with RPG elements, trading, plenty of loot to acquire, and planets to explore. It certainly looks more arcadey than something like Elite: Dangerous or Star Citizen, but that could be a good thing.
If space sims and sleuth-focused adventure games aren't your cup of tea, Ghostrunner's demo might be worth a look. The fast-paced cyberpunk action-slasher will see you running on walls, dashing through the air, and sliding under obstacles as you annihilate your enemies with a powerful katana. One bullet is usually enough to finish you off in Ghostrunner, so agility and, of course, trial and error, will serve you well.
For a more complete look at what Steam's Autumn Game Festival has to offer, visit the official page right here. As usual, the latest Game Festival will only last about a week (it ends on October 13), so be sure to check it out sooner rather than later.