Currently in Early Access with Native Linux support and rated Steam Deck Playable, the inventory management roguelike Backpack Hero is releasing in full in May.
Alina of the Arena looks like a lot of fun if you love your deck-builders, and a recent update should make it a lot better on Steam Deck (and Desktops with a controller).
Dead Cells: Return to Castlevania is shaping up to be the most exciting content expansion to Dead Cells yet and we don't have long to wait now as it's releasing March 6th.
Anodyne from Analgesic Productions recently celebrated a 10th anniversary, and the community delivered in style with a full fan remake for modern platforms thanks to the previous source code release.