Like others said, any turn-based game. Currently suffering enjoying SMT III Nocturne, others I’ve played are Octopath, Fire Emblem, Pokemon (esp Mystery Dungeon), Atlus in general. Balatro sounds nice. Rhythm heaven is WarioWare + Music, and that’s definitely doable one-handed, especially the Wii version. My mom said Fortune Street (Monopoly but Mario + Dragon Quest) lol.

Mobile games can be very doable, a cute one I remember is Candies n’ Curses, a game where you swipe to direct the character around a haunted mansion and fight bosses. Easily can be played with one hand. If you can tolerate gachas, Cookie Run Kingdom can be put on auto so you don’t have to tap much, I just like the story and characters. I think Geometry dash can be doable on low levels with one hand?

Find your inner weeabo and play some Japanese visual novels. Or if you’re a normal person then Ace Attorney would be a fantastic choice, and is a long-ass series. Prepare for courtroom bullshit and jokes.