Modern web browsers do not let websites play sound without user interaction or display bunch of popup dialogs, so you need to interact with the website (click around, allow popups etc.) in order to get the "full experience".

And also you may want to turn down the volume!

When you are ready, click here to visit the website

Use killall command to kill your browser:

killall -9 firefox

Or use the task manager if you are on windows. Another option is just to wait untill your browser or your computer crashes.