Valve has released a breakdown of the top selling games on Steam so far in 2018, notably including recent release Jurassic World: Evolution.
Jurassic World launched less than a month ago, but has already apparently sold well enough to merit recognition alongside expected 2018 top sellers such as Grand Theft Auto V, PlayerUnknown's Battlegrounds, and Dota 2. Indie car soccer game Rocket League retains its popularity on the list as well.
Kingdom Come: Deliverance, Vermintide, and Far Cry 5 were the only other 2018 releases in the "Platinum" category of top sellers with Jurassic World. Beneath them in the "Gold" tier among older releases are 2018 games Dragon Ball FighterZ, Final Fantasy XV: Windows Edition, and Subnautica (which launched out of a years-long Early Access campaign).
Steam did not specify what qualified a game to be in the Platinum tier as opposed to Gold, Silver, or Bronze.
Slightly more specific numbers were given in another celebratory list of the games with the most simultaneous players so far in 2018. Dota 2, GTA V, Counter-Strike: Global Offensive, PUBG, Tom Clancy's Rainbow Six Siege, and Warframe all, at some point in 2018, had over 100,000 simultaneous players.
Beneath these giants, the next tier (with 50,000 or more simultaneous players) includes indies Stardew Valley, Subnautica, Garry's Mod, and Rust. Skyrim is also in this category, offering an unsurprising explanation for why the game continues to receive ports to every platform imaginable.