Runs great on Steam Deck, I've played 40+ hours. You will have to log into the Ubisoft launcher the first time you try to run the game, but after my first time logging in I never saw the launcher again. The only issue is that the game crashed intermittently until I went into SETTINGS > ONLINE and turned everything there OFF. My theory is that the game was trying to trigger online operations, which was causing it to crash. Once I disabled all online stuff, it has run great and I've never had a crash. Super fun game as well if you like big open-world exploration, collecting and just general messing around, as I do. I've aleady beaten this game previously on my desktop PC years ago, and since I almost never did online stuff anyway, I can say my experience on the Deck is almost exactly the same, except now I can play this game in bed, lol. :)