S.K.
M., Good morning! I have a couple of ideas for you - the first is a game some friends came up with for one of my birthday parties. You make up a list of questions, which can be about any subject (one of mine was what would you do if a monster crawled out from underneath your bed?), then you write down an answer that makes sense to that question. You cut the questions and answers apart and mark the back of the little strips with either a Q or an A. You fold each strip in half, then place the questions in one bowl and the answers in another. You have someone at one end of the table draw a question and read it, then someone at the other end draw an answer and read it. Of course, rarely do the answers make sense for the question, but some of the resulting combinations were hysterical.
Also, have you ever played Bunko? That's another game that large groups can play and all it requires are dice, a timer, paper and pens. You can buy the game at Wal-Mart and it's fairly inexpensive, but you'll need multiple sets as you need one set of dice per table of four people. The group I used to belong to also purchased inexpensive gifts to give out at the end - one for the winner, one for the lowest score, one for the most Bunkos, etc. I think there were five or six gifts in all and they ranged from scented soaps or candles to kitchen gadgets - nothing overly costly.
I hope one of these helps and I pray you have a truly wonderful, blessed retreat!
Oh, one more idea...my daughter and I just got Don't Forget The Lyrics and it's so much fun! That might be another idea. At any rate, enjoy! God bless! S.