>>14567771
Ok, here's the deal:
You're already on the right path by getting a gameboy emulator.
You see, games made for handheld devices are usually designed differently from home console/PC games, they're easier to pick up and play with simple gameplay/controls.
However, on mobile phonew devices a trend started where games treat the consumer as absolute shit, and just focus on ways to make quick cash instead. So you had some early games that were actually games like Angry Birds and Plants VS. Zombies, but nowadays it's pure Gacha online-only bullshit that wants to milk you for ads and microtransactions.
So gameboy, gameboy advance, DS and PSP games emulated on it will be your best bet. Just be wary of the touchscreen controls and the limitations of it, no games that require fast and precise movements. I've been playing GB's Game & Watch gallery just fine on my phone and cleared Donkey Kong 98 with no problems, you just need to configure the on-screen controls in a way you're confortable with. RPGs are always easy to play on touch controls and DS touchscreen focused games like Ace Attourney, Professor Layton and Ghost Trick play really well.
You can still browse the appstore to see if you find something that catches your eyes, but you won't find much other than dozens of games promising you waifus but then making you realize they're not real games at all, just menu simulators.
You can also get stuff like Teaching Feeling and maybe even Corruptions of Chapions in it, those kinds of games are surprisingly handy to have in your pocket at all times.