There’s growing evidence, via datamining and voice actor leaks, that Valve is working on a brand new, yet-to-be-announced Half-Life video game. And before you go running to tell folks that, finally, Half-Life 3 is confirmed, keep in mind that we don’t know if that’s true.
"Basically, fast-paced interesting ADHD gameplay. Combination of Dota 2, Team Fortress 2, Overwatch, Valorant, Smite, Orcs Must Die."
That's how notable Valve leaker "Gabe Follower" describesDeadlock, a Valve game that is seemingly in playtesting at the moment, for which a few screenshots have leaked out.
The game has been known as "Neon Prime" and "Citadel" at prior points. It's a "Competitive third-person hero-based shooter," with six-on-six battles across a map with four "lanes." That allows for some of the "Tower defense mechanics" mentioned by Gabe Follower, along with "fast travel using floating rails, similar to Bioshock Infinite." The maps reference a "modern steampunk European city (little bit like Half-Life)," after "bad feedback" about a sci-fi theme pushed the development team toward fantasy.