"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" describes Deadlock, 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.
they probably got confused and meant to say Half Life 2's art direction, which was headed by the same guy who was behind the art direction of the first Dishonored game.
While both games sport a lot of incredibly similar stylistic choices, only Dishonored fits that ''european city steampunk'' description, and even then, D1 is more Oilpunk than steam.
spoiler