Indeed it creates an flatimage, a file containing a base linux install and a runner of your choice. Wine staging for instance (Emulators also). You can add programs and or games to the package. Creating a one click solution to run software/game(s) without the need of aditional configuration afterwards like with lutris.

Works on all distros

For more info have a look over here: https://github.com/ruanformigoni/gameimage