My most played game was Like a Dragon Infinite Wealth, followed by Metaphor ReFantizio, both excellent games, as well as being new releases that run well on Deck.
Some lesser played games I would really recommend:
- Demon Tilt/XenoTilt - really cool pinball games. Play great on deck, and are great for short high intensity play sessions.
- Shadow's of Doubt - I've recommended this a few times, it's a full simulation detective game. Solve serial murders in a city where every NPC has a fully simulated life routine. You can roleplay it different ways, but it's easy to fall into a Rorshack style of detective, breaking into crime scenes, cleaning their fridge out of beans, and robbing the house blind as you hunt for clues.
- Pseudoregalia - Short but great 3d metroidvania, with really great freedom of movement. One of those games where moving around itself can be a joy.
- Yellow Taxi Goes Vroom - delightful 3d platformer, has fun movement and is a really happy game.
To be fair, most phones don't have easily replaceable batteries anymore either. I remember in an interview that one of the steam deck leads said they really wanted an easier to replace battery, but it was a compromise they ended up making. I think they blamed it partially on inexperience with hardware production, and that they hoped to do better on future hardware.