Maybe not so much an actual bingo game where there's a host reading out results, but I think a social bingo game could be a really fun way to get characters mingling/meeting each other! One of those things where the squares are stuff like "compliment someone you haven't met before," "meet someone who has more than two siblings," "confess something to someone," "play a round of truth-or-dare with a new person," etc. etc., and the people you play with sign off on your card. That way it could be competitive (first person to bingo/blackout wins first prize!) or just a good hook for characters to thread and meet each other!