The spans have classes `gamelist_lobby_players` and `gamelist_lobby_spectators`, shouldn't be too hard to check those.

`return !(filter.test($('.gamelist_lobby_players', this).text()) || filter.test($('.gamelist_lobby_spectators', this).text()));` or thereabouts.

That said, this does let you search for weird things, like player count and score limit... I guess it's fine like it is.