Gaming

Factorio would be perfect to let it play itself after you are far enough into the game. Play on peaceful mode so that you don’t have the enemies destroying your buildings

Try out some incremental games! Some good popular games in the genre are Cookie Clicker, Realm Grinder, Antimatter Dimensions (and its mods), and there's a whole world of little niche incremental games out there waiting to be discovered.

I would check out r/incremental_games for games like that. We're starting a community for it here on lenny !incrementalgames@lemmy.ml.

Edit: It was called 'soda dungeon'.

https://play.google.com/store/apps/details?id=com.armorgames.sodadungeon

Iirc in 'Pixel dungeon' you can auto play after you have levelled up a bit manually.

Pixel Dungeon (Rogue-like) https://f-droid.org/packages/com.watabou.pixeldungeon/

You can set up afk farms in Terraria to find rarer items :)

Give Hitman WOA a try

Rimworld, at the later hours of a colony, becomes more of an idling game. Mods make it even more so by making your pawns and defenses insanely overpowered. My late game colonies usually have 5-10 brawlers that absolutely shred everything.

A little late to the party, maybe you've found your game already and I'm not sure if this is what you search for, but what I did, while writing my master's thesis, was playing Stardew Valley.

It's cozy for the most part. The game auto saves after you finish an ingame day (it saves when you wake up the next morning if I remember correctly). Days were for me roughly 15-25 minutes, depending on how far I was in the game.

So what I did was play a day in Stardew Valley, then write my thesis for a while, play another day, write my thesis, play two days, write my thesis and so on. (I admit, there were days where I played more, but hey, I finished my thesis!)

A bit late, but hypixel skyblock may fit (it's a minecraft mmo based on 1.8.9) which has many idle game components and many ways to play while active

If you want to ruin your life, there's always Eve Online. There's lots to do when checking it infrequently (mining, selling/buying stuff, etc.). You can then play actively for PVE content and PVP.

Tagpro.gg

Action web game with a simple concept but difficult to master. Good for a study break because you can play a couple matches within 15 minutes.

Bitburner is a kinda fun idle type game.

Rimworld on 1x speed and on a lower difficulty. Spend some time setting up your farms, materials, buildings and research, and let your colonists deal with it while you study. Bonus points: the music is relaxing and really good.

You'll get a couple bad events every hour and probably will need to be on top of food for a while but on a lower difficulty with custom settings, you'll be fine.