Valve/Steam do a handheld thingy

[Jacob]

There's the Asus ROG Ally and Lenovo Legion Go as well...

[Josquius]

It's the greatest handheld gaming device since the original Game Boy.

It is great. Though I'd liken it a bit more to the Game Gear. The battery doesn't last too long.

[The Minsky Moment]

The battery will last pretty long if you stream, remote play, or play lowfi games natively, especially for the OLED model. For high end games, I usually run through GFN and get 6-8 hrs. The downside though is that you can't easily access game-specific community control schemes, and of course you need to be able to access really strong wifi in the location you're playing.