I stumbled across this Wikipedia article about a handheld from the 90s that looks quite unique to me.
It’s called the TurboExpress, but the article itself is quite short in my opinion, and apparently contains information that may not be accurate. 
If anyone has ever owned one, or knows of a good source of info on the thing, I’d be interested in hearing about it. I’ll keep looking on the web in the meantime.
I’ve played one at a computer museum fair here in the UK.
Probably amazing for it’s time but these days bad screen and bad battery mean I didn’t think much of it.
More info including links to magazine pages
https://www.head-fi.org/threads/the-turbo-express-my-portable-gaming-obsession.774057/
I’ve seen a couple of PC Engine GTs in my time, but they didn’t work.
It’s funny they were ‘cheap junk’ for a minute in like 2006 due to all being dead.
Played on one a bit back in the early 90s. It trully was amazing back then but as screens improved the obvious flaws became apparent. Still, with a screen mod it’s still quite a nice system and with a Everdrive attached you can have your entire PC Engine collection on the go.