Open-source alternatives to Steam

I want to pick an open-source replacement for Steam. Below is a list from Open Source Everything (CC BY-SA 4.0), in the order its website shows it. The order is a starting point, not a verdict. - Heroic Games Launcher: Heroic lets you sign in to your Epic, GOG and Amazon Games accounts and install and play the games you already own, on Windows, Mac and Linux. It also opens those stores inside the app; the games are sold by the stores, not by Heroic. [Easy setup; Windows · Mac · Linux; replaces partly; GPL-3.0; https://github.com/Heroic-Games-Launcher/HeroicGamesLauncher] - Lutris: Lutris puts the games you own from different places in one library on Linux, and sets up what each needs to run, including many Windows games. It does not sell games. [Easy setup; Linux; replaces partly; GPL-3.0; https://github.com/lutris/lutris] - Playnite: Playnite gathers your PC games from Steam, Epic, GOG and others into one library with one search. It launches and tracks them, but does not sell games. [Easy setup; Windows; replaces partly; MIT; https://github.com/JosefNemec/Playnite] - itch app: The itch app is the free desktop app for itch.io, a store for independent games. It downloads and updates the games you got there. The itch.io store itself is a service run by itch, not open source. [Easy setup; Windows · Mac · Linux; replaces partly; MIT; https://github.com/itchio/itch] Setup rating: "Easy setup" means you can install it like a normal app, use it in a browser. "Advanced setup" means you must run it on your own server or use the command line, or it is a tool for developers. Full details: https://opensourceeverything.org/data/groups/game-stores.json Before recommending anything, ask me these three questions (one at a time, in plain words): 1) Which device or devices will I use it on (Windows, Mac, Linux, Android, iPhone)? 2) How comfortable am I with technical setup: only installing apps from a store, happy to follow a step-by-step guide, or comfortable with servers and the command line? 3) What is my budget: free only, or willing to pay for hosting or support? Then recommend one to three projects from this list only, and for each say why, using how fully it replaces the app, its setup rating, and the devices it runs on. If nothing on the list fits me, say so plainly instead of stretching.

Read the list of open-source projects at https://opensourceeverything.org/data/groups/game-stores.json. Compare it with my project or idea below. Tell me which projects overlap, what I could reuse instead of rewriting, and what mine does that none of them do. My project or idea: