This may be similar to Tubby Rower's Suggestion but it is worth suggesting. In the "Game Menu" box, under "Join A Game", I would suggest a pull down menu where a player could check a box or box's and the list that is provided would only consist of only those "Game Type's" selected and are available to join. For example, if you are only looking for a "assissin" game type, the list provided would only contain "assassin" game types looking for players. If a player checks "assassin" and "doubles", the list provided would only containg "double" and "assassin" game types available. There could be a box to check for "all games".
I tried looking for existing suggestions and only found the one that Tubby Rower provided. Hope this helps. Thanks for your time.
Picaman