D.B.
Water balloon toss and an egg toss are both great ideas. I would not do the egg thing in the jump house. If your jump house is returned with egg in it, they may come back and charge you for damages.
I remember playing a football toss when we were kids. You use a hula hoop either held up by someone or something and then you have to toss the ball thru the hoop.
Mummy game is fun for all ages. With 17 boys you could make 5 or 6 teams, each gets a roll of toilet paper, each team picks a person, within their team, to get wrapped, then the first team to unroll the entire roll around their selected team mate wins. It's fun and crazy at the same time.
Have fun...not sure what's worse 17 preteen boys or 17 preteen girls. lol You are a brave mom! Have fun! I hope it doesn't rain.