The game is Stray. Developed by Blue Twelve. Published by Annapurna Interactive.
https://en.wikipedia.org/wiki/Stray_(video_game)
Without spoiling anything, there's way more to this than just a cat simulator. Loving it so far, in any case. I recommend this to anyone who loves exploring new worlds, interacting with lots of locals, solving puzzles. Everything about it has both a familiar RPG feel and also a sense of new to it. And it plays really well on Linux via Steam.
This game is such a great, short experience. Reminds me of Portal in that sense. It really hits you in the feels at several parts. Runs perfectly on the Steam Deck.
Yes. In fact, as it ended, I hoped it would have a "this is a triumph" kind of ending song too. :)
This was the first game I played on my Steam Deck when I got it! Had a tiny bit of trouble with lagging, especially when there were a lot of enemies on screen, but some tweaking in the settings fixed it. Had a lot of fun with this game, though!