Seems if you want to do a little space exploration and building, No Man's Sky might be the place to be - with the Sentinel update out now. This brings with it enhancements for the Steam Deck.
There is of course a huge amount of other changes, but we have a special interest right now for obvious reasons. Hello Games noted that it will "support Steam Deck from launch" plus it has: a number of specific Steam Deck optimisations, support for Steam Deck controls and support for Steam Deck touch input. So they've clearly put some effort in on this one.
As for the content included there's multiple fierce new robotic enemies, Multi-Tool overhaul with a new Neutron Cannon weapon, AMD FidelityFX Super Resolution support, a Cloaking Device, a new Exobiology Expedition, an overhaul to the combat systems, NVIDIA DLAA, more companions and the list goes on.
On their special update page, the title for the Steam Deck section is "Native Steam Deck Support", although it's not clear what kind of "Native" they actually mean - as right now there's still only the Windows build on Steam. It's most likely they mean supporting it through Steam Play Proton, just with their Deck-specific upgrades.