> disable your adblocker when visiting that website, or you'll see only an empty page with a countdown.

Thanks for the heads-up. Will not visit site.

what happens at the end of the countdown?

The site has a little game where you click to dismiss as many cookie-consent popups as possible, in 30 seconds. I suppose if you can't see the cookie consent popups, then at the end of the timer you just have zero points.