In an interview not long after the steam deck handheld was announced, a developer revealed that the Steam handheld can play the entire Steam library, the latest game is no problem, and now V is delivering on its promise. At present, Steam Deck verification can be found in the background through the database SteamDB, and the list only contains games that currently have V society certification and can be played on Steam Deck.
Only a small percentage of games can't be played on Steam Deck, including Persona 4 Gold Edition, VR games Budget Cut, Job Simulator, theBlu, and Arizona Sunshine.
As for why Persona 4 Gold Edition (P4G) does not support Steam Deck, the company has not given a specific reason. The page only shows "Valve's tests indicate that the game does not support Steam Deck, and part or the whole of the game cannot run on Steam Deck", and that "Valve is still trying to add Steam Deck support to the game".
Some games also have some features that are not supported for the time being, such as The Witcher 3, The Killing Spire, Temple of Heroes, Factorio, and Tomb Raider: Rise. The Steam Deck Support pop-up window for all games will indicate which features of the game are not currently supported or cannot be fully adapted.
If all icons have a green tick icon, it means that these games can be played smoothly on steam Deck. Such games include Final Fantasy: Pixel Remake, Dark Souls 3, And Hollow Knight, and more.