The past few months I’ve been developing a multiplayer card game very well known in south america called Truco for a link sharing portal which has a lot of traffic.
The game and site is in spanish, and the game is not trivial to learn (although it isn’t complicated at all, rules can be found here, or you just can go in, chat a little and throw some cards at random and see what happens 
The game was made with PulpCore and Apache Mina
Play the game here (no need to register in the site, if you log in as guest, remember to create rooms betting 0 points, or join rooms that bet 0 points)
Cheers!