Shattered pixel dungeon is fun little rougelike dungeon crawler

Emulation is a great idea. Dead cells is pretty fun on the go. Slay the spire will also kill a lot of time plus easier to play on a plane probably.

Siralim Ultimate, Mindustry or ReFactory, Wreckfest

Dungeon Maker is a fun little roguelike/strategy game I've been playing atm https://play.google.com/store/apps/details?id=com.GameCoaster.DungeonMaker&hl=en&gl=US You hire and level monsters whilst building a sorta dungeon with traps for heroes.

Since you mentioned Minecraft and farming simulator, both Terraria and Stardew Valley are on android, though I can't speak for their quality or playability.

Emulators are a pretty good shout, PPSSPP was pretty great when I last used it which was a few years ago now, so I imagine possibly better now and the PSP had a decent selection of games.

You could also try Google Play Pass for a month and look at a few paid games and see if anything tickles your fancy there, but subscription service.

Grand Mountain Adventure, its fun, you can play it in bursts or over longer periods and has a catchy soundtrack!

If you've got the cash I think the Steam Deck is still discounted. With that you could play all the games you listed.

If not, Shattered Pixel Dungeon is awesome. And people seem to like Mindustry. I haven't tried the latter yet. You can find lots of games without any bullshit on F-Droid.

Monument valley 1 and 2 are both beautiful