Note by @fastfinge

@quanin @mcourcel Okay, here's a list of the games I have:
* Alcyone: The Last City: fully playable, but only with annoying SAPI text to speech
* Alt-Frequencies: fully playable
* Arcade Spirits: fully playable, outputs text to the clipboard, so you need autoclip
* Arcade Spirits: The New Challengers: same
* As Dusk Falls: fully playable
* Balatro: you need a mod but installation is easy
* BROK the InvestiGator: fully playable
* Citizen of Rome - Dynasty Ascendant: fully playable
* Conjury: fully playable
* cyberpunkdreams: fully playable
* Dark Passenger: fully playable
* Diablo: mostly playable
* Doki Doki Literature Club: you need a mod and installing it is irritating
* Doki Doki Literature Club Plus!: this is a remastered version of the above game and the mod is much easier to install and better in every way
* Escape from Norwood: fully playable
* Factorio: fully playable with mods
* Firebird: fully playable
* Forza Motorsport: fully playable
* Hearthstone: fully playable with mods
* Heroes Rise: The Prodigy: fully playable
* Kilta: fully playable
* The Last of Us™ Part I: fully playable
* The Last of Us™ Part II: fully playable
* Lost and Hound: fully playable
* Luck be a Landlord: fully playable
* Magic Research: fully playable
* Magic Research 2: fully playable
* Microsoft Flight Simulator: only playable if you devote your entire life to it and pay a monthly subscription for the mod and make the correct pagan sacrifices
* Night of the Full Moon: fully playable
* Penny Larceny: Gig Economy Supervillain: fully playable
* Periphery Synthetic: fully playable
* Pizza Game: fully playable
* Sanctuary in Time: fully playable
* The Secret of Darkwoods: fully playable
* SEQUENCE STORM: fully playable
* Shining Song Starnova: fully playable with autoclip
* Skullgirls: fully playable if you own a controller
* Slay the Spire: fully playable with a mod called say the spire
* Smugglers 5: Invasion: playable if you like using object navigation and OCR
* soundStrider: fully playable
* Stardew Valley: playable with mods
* Thaumistry: In Charm's Way: fully playable
* Trawel: fully playable
* Warsim: The Realm of Aslona: fully playable
* World Empire 2027: fully playable

I would recommend sequence storm as your first place to start. Good fun, finishable in a few days, requires no modding. Then maybe move on to Slay The Spire and Balatro to get used to modding stuff and how that feels. Both excellent games that take months to master. There are many more mainstream accessible games, these are just the ones I've personally played.