Probably Cross Code, Trails in the Sky or P4G that are collecting dust in my Steam account.
I haven't played on PC for a long time already (work leaves me unwanting to touch a PC really); so I will look into some other games to play later. Perhaps Outer Wilds. And sure some older games.
Hmm... perhaps there should be a forum here on "interesting PC games to try on the Steam Deck" both old and new, divided by genre. I would go in there to get some ideas. It would probably seem silly, you know all these PC games have been available for ever, but a nice reminder anyway for the forgetful ones. And talking about games that have been available for ever I will make sure Cave Story makes its way inside. I would also like to put some Forza Horizon on it, 4 would do, but TBH I like 2 the most... too sad it's not on PC... Perhaps I will put Dolphin on it and use to finally complete Geist, that I never did... but I think I am the only person that likes Geist... Well, enough random nonsense for this post.