Steam Deck verification includes things like text being legible and buttons showing up correctly in prompts and mapping, etc. For example, Civilization VI has a Linux native version but is not verified because some game text is too small, and it might require some typing using the virtual keyboard which may not pop up automatically when required.
I know, that is what I meant with “checkmark of a few important points”. But the game can run horrible, due to bad optimization leading to bad performance in example. Lot of people think the performance is the verification process, but it isn’t. I was talking about the misconception about performance factor.
That’s because performance is a criteria for getting verified:
default configuration: the game must ship with a default configuration on Deck that results in a playable framerate.
Source: https://partner.steamgames.com/doc/steamdeck/compat#DeckCompatibilityChecklist
There is no “target framerate” though, so what’s considered “playable” differs from tester to tester.
