Steam Deck continues to be a fun way to get some game time in from my Steam back catalog, and I have a few more tested and reliable suggestions for those interested:
Quake
What it is: inventor of the boomer shooter along with Doom and Wolfenstein; only played in single player mode on the deck.
Why Play on Steam Deck: Super smooth framerate and the Steam Deck controls were made for FPS gaming, very responsive in the right way.
Possible Issues: I bet the multiplayer doesn't work properly. Will have to try it out.
The original Quake (well, its remastered version) seems to run fine on Steam Deck. My suspicion is its not currently rated for it due to online functionality issues, but if you play the offline campaign mode it feels great, extremely responsive. Indeed, the Steam Deck has become my favorite way to play boomer shooters, and Quake is the commander in chief of this genre (Doom being the....five star general?). I plan to test Quake II as soon as I finish with Quake. Last time I talked about the Steam Deck I also advised Prodeus as a good choice...that still holds, Prodeus feels very optimized for the Steam Deck, runs great and is fun to play on it.
The Moons of Madness
What it is: single player story-driven experience with light puzzle elements
Why Play on the Steam Deck: Immersive blend of SF and horror storytelling conveys well in a very personal way on the Steam Deck, this game got me through a weekend cold.
Possible Issues: I experienced one or two moments of framerate drop at odd moments, but I also ran this game for 11 hours straight from start to finish, so it may have taxed the program a bit.
I had this game in my library for ages, and finally decided to plough through it. Turns out, Moons of Madness was a great experience on the Steam deck and a very interesting story-based walking sim with light puzzle elements, focused on a (SPOILERS) scifi take on the Lovecraftian mythos. I had no idea it was rooted in the mythos when I started playing, so discovering this organically was very satisfying. It took about 11 hours to complete.
The Ascent
What it is: isometric action RPG with cyberpunk/far future SF theme; multiplayer available but I only played single player.
Why Play on the Steam Deck: Extremely compelling gameplay makes this incredibly fun, and its graphics really shine on the Steam Deck without any framerate loss I detected.
Possible Issues: some real small text, but Steam Deck's magnify feature works with this.
This top-down isometric shooter with RPG elements is the most atmospheric Cyberpunk/SF experience you can get outside of playing the actual Cyberpunk 2077 game, but with the addition of a very satisfying gameplay experience meshed with a rather elaborate story about a distant arcology/station on an alien world suffering from a collapse in power, authority and resources and the scummy cyberpunks who try to profit from it. I had overlooked this game, and glad I discovered it at last, well worth playing through. You can play multiplayer and its green lighted for the Steam Deck, too. About the only issue is there can be some small text on screen, so keep that in mind.
Tales of Arise
What it is: action RPG anime style; single player only (so far as I can tell)
Why Play on Steam Deck: If you want a good looking JRPG to play on the Deck with a compelling story, the Steam Deck provides the right level of interpersonal immersion on-the-go. But seriously, get this game even if you don't have a Steam Deck.
Possible Issues: none so far.
I'm in the middle of this one and unexpectedly enjoying it. After caving on this one with a recent sale, I was a bit concerned it would be yet another bog-standard JRPG with arcane mechanical contrivances to attract veterans to the combat system, but simultaneously becoming out of reach for more traditional or newer gamers. In fact I played the demo and came away worried it wouldn't be that fun....but I was completely wrong, and the game's much better and more organic actual introduction/tutorial region (cleverly disguised such that you won't even notice it is a tutorial) does a great job introducing you to the mechanics and how combat works, and its a lot more traditional than I expected while still being a compelling quasi-action RPG style meshed with a really fascinating story, world and characters. A+++ and plays great on the Steam Deck.
Important to note! If you are like me and tired of most JRPGs starting with a gang of teenage or subteen protagonists, you'll love this one, as the average character is at least in their twenties or older (so practically geriatric by anime standards!) and the storyline is presented in a keenly intelligent manner with excellent voice acting.