Well there's a surprise. Horizon Zero Dawn Remastered from Guerrilla Games / Nixxes Software and PlayStation Publishing has been given the Steam Deck Verified tick from Valve.
Despite the game bringing in some more enhanced rendering and updated graphics, it appears it's running well enough for Valve to think the "game works great on Steam Deck, right out of the box". It does, however, need an internet connection for first-time setup thanks to the forcing of a PlayStation Network Account.
The release came with Ultrawide 21:9 and Super Ultrawide 32:9 resolutions, as well as 48:9 triple monitor support, NVIDIA DLSS 3, NVIDIA DLAA, NVIDIA Reflex, AMD FSR 3.1 and Intel XeSS. So if you're playing on Desktop Linux with Proton you've got plenty of options to tweak it to your liking.
Have you been playing on Steam Deck / Desktop Linux? How's your experience been?