When the project is built for WebGL, the Meniu window is shown up. When you press the button "Start Game", a new window shows up for a second and backs to Meniu window (WebGL.gif). The project in Editor (Play mode), works correctly (Editor.gif). Also, when the project build for PC, everything works correctly too (PC.gif).

Reproduction steps:
1. Open the folder "builds" in the attached file;
2. Open the folder "galaxy_pac_man_Data";
3. Play index.html in a browser;
4. Press the button "Start Game";

Actual result: the new window shows up for a second and backs to Meniu window.
Expected result: after pressed "Start Game", the new window should load.

Reproduced with: 5.4.1f1, 5.5.0b11, 5.6.0a3.
I couldn't reproduce it with older versions because the error "The browser could not allocate enough memory for the WebGL content" is shown up which was fixed in 5.5.0 version.

Resolved as By Design because the user used not weighty condition (if (!playerAudio.isPlaying)) which backs to the menu window.