I love my Steam Deck. I actually had mine imported from the UK since they weren't easy to buy here in Norway. Having a small, always available handheld PC made me finish some great big and small games last year.
When I started creating Cascadou, I knew I wanted it playable on the Steam Deck. That meant keeping the graphics crisp and clear, font sizes up, and an easy control scheme. The Cascadou beta has been playable on the Steam Deck pretty much from the start, and I think it's a game that fits really well on the console.
I haven't yet looked into Steam Deck verification, but I can guarantee that it will play well on the deck. It is my preferred testing device, so if you have a PC with similar specs you know you will have a nice time. Performance wise it is running at 60fps at the moment, and I hope to keep it that way.
Basically you only need two inputs, one for lifting/swapping a card, and one for setting off a chain. And of course using the dpad or left stick to hover over cards. Touch screen also works pretty well, so that could also be a way to play.
Do you have a Steam Deck and have some special needs or wishes? Let me know!