HaxBall is online multiplayer sports game.
This game is not mainstream but it is still played all around the world!
You can play two versions in your browsers nowadays.
In this game there are many leagues – national, international, there is also HaxBall Champions League and international representation tournaments.
The league with the greatest tradition is http://fm-haxball.co.uk/ On their TeamSpeak server there is the biggest activity – ts3 adress: fm-haxball.co.uk
You can watch streams and videos from HaxBall here: https://www.youtube.com/c/PecikTVHaxball