Quoting here, because it is impressive.
Legendary - A free and open-source replacement for the Epic Games Launcher - GitHub - derrod/legendary: Legendary - A free and open-source replacement for the Epic Games Launcher
github.com
A games launcher for GOG, Amazon and Epic Games for Linux, Windows and macOS. - Heroic-Games-Launcher/HeroicGamesLauncher
github.com
I have not tried the GUI yet. I have only tried the command-line. If you have already Python, it is sufficient to run:
followed by:
Then you get redirected to a webpage where you can find the authentication key ("sid"), copy it into the command-line, and that is it.
You can then list all your games:
Install a game (or import it if it was already installed), update it, launch it, etc.
You can even download all of your cloud saves, which is something you could not do with the official launcher!
Edit: I cannot download the cloud save for a game which I never installed on my desktop computer and have only played on Geforce Now.
Edit²: Apparently, Geforce Now takes care of the cloud save, instead of Epic! So I cannot download the save with this tool!