My SO and I have been having a lot of fun playing co-op games on the Steam Deck connected to the TV. We recently finished Split Fiction and I'm looking for the next cool experience to try out. We enjoy casual co-op games, nothing too hard or violent. EDIT: pixel art is apparently a big turnoff for her so that's out as well.
Games We Enjoyed:
Split Fiction
It takes two
Untitled Goose Game
Games that flopped:
Stardew Valley - She is open to "farming" games but doesn't enjoy the energy management aspect of the game. It also gave her motion sickness, somehow
Overcooked / Moving out - We enjoy these games but as they start to get more chaotic and hard, the enjoyment goes way down
Ibb & Obb - A bit dull and samey
Portal - Gives me serious motion sickness, completely unplayable
Lego Lord of the Rings - I'm a lord of the rings fan but I hated the gameplay for this game, I found it to be so boring. We quit after an hour or so.