Playnite is a free, open source gaming application for Windows, Linux and macOS. It allows gamers to manage their video games library and provides access to various gaming services and platforms. It includes a centralized library of games with support for various platforms, a unified user interface, custom themes, game time tracking, game statistics, and game customization. Playnite also provides support for various launch parameters, mods, and cheats. It also offers automatic game updates, cloud synchronization, and more. Playnite is a great tool for gamers who want to keep track of their games, play them in one place, and keep them up to date.
It is actually a game launcher, probably the biggest one for Linux. It has an emulator and normal Steam / GOG support, it is also open source.