Main menu as in not just a MOTD kind of thing but being able to get into the game at all? Seems a bit spooky that a webpage can hook into the game like that. Ripe for exploits

Something similar happened in a HL2 mod I worked on many years ago. We just pointed the MOTD window to our website. Then the mod got super popular, which the site couldn't quite deal with. Static motd.html shipped with every version after that 😂