The Window Menu allows you to change Game Files if Multiple Game files are loaded into the Editor.
Clicking on Game will bring up the following menu list;
Currently Not Supported.
This Part of the Menu shows all the Game Files Currently Loaded into the editor (as the editor can load multiple files at once). The currently Active Game File is Marked with a Tick.
The Window Title, composes of the Game File Name / The Level Name and the index of the Current Level Index in the game file out of the total number of Levels.