The gaming Client designed for a convenient purchasing, playing and updating games, as well as an online play between gaming platforms, GOG Galaxy is also built with optionality in mind, and a belief that you should own the games you buy.
This is the Windows version running via WINE. It is experimental. Some games may not work correctly, or at all. Your mileage may vary.
Some games might require you to run snap connect gog-galaxy-wine:hardware-observe, and/or snap connect gog-galaxy-wine:process-control in a terminal (or use the Software Centre in Ubuntu 18.04 to toggle "Access to hardware information" and/or "Pause ro end any process on the system") to grant extra permissions for the application. Though all the games tested so far do not need these permissions.