@akahohum. Sorry for the agony. Most probably, the firewall blocks the multiplayer conexion.
Maybe, we should add an option to allow playing at least the single player mode in case of not being able to connect to the multiplayer game.
What "FYI" does mean?
There are positive opinions and negative opinions. Both are welcome and I won't comment any opinion in particular. But there are 2 points that I think it is necessary to clarify. First, the full game is completely free. The only required thing is to register on the site, specially to handle users decks and multiplayer sessions. So, players don't have to pay to play the complete game. The second point is music. This sound is on other games (more than one) and will probably be on more games, but not because it has been stolen. This music comes from shockwave-sound, a site where musicians sell their music to anyone. The creators of the game paid for that music on that site (most probably as the other games did) and have all the permissions to use it in the game, so there is no Copyright Infringement. I think this point was important and had to be clarified. Maybe I should have mentioned it on the description, I didn't think about it, but I hope now it is clearer.
Hi eequ.
There is a mute button, but you only see it when you pause the game (pressing SPACE). You can choose the volume of the music and/or the sound.
 "Mega Doyu Golf"){kind=icon}
 "Multiplayer 9-Ball"){kind=icon}
 "Doyu Card Battle"){kind=icon}
 "Boxhead: The Zombie Wars"){kind=icon}
 "Doyu Golf"){kind=icon}
 "SHIFT 4"){kind=icon}
 "Digit Twins"){kind=icon}
 "Minions"){kind=icon}
 "Super Stacker 2"){kind=icon}
 "Roly-Poly Cannon"){kind=icon}
 "Mechanical Commando"){kind=icon}
 "Hanna in a Choppa"){kind=icon}
 "99 Bricks"){kind=icon}
 "Microbe Kombat"){kind=icon}
 "Doyu Jump"){kind=icon}
 "Wheel Of Death"){kind=icon}