I see you call yourself 'MagicMan'. Do you do magic tricks? Those are always a huge hit with kids.. and adults! With it being Summer, water games are always fun, especially if your party is outside.. sprinklers, a water balloon fight, or throwing contest, bobbing for apples, water guns, the trusty old slip-n-slide... bubbles! Just plain swimming is so fun for kids on a hot day... 'before the cake and icecream of coarse.' If you have the cash, you could get a cotton candy machine for the day too, and whip up some cotton candy for everybody! Kids are always fascinated by that kind of thing, plus they get to eat it!
Hope this helped you.. I hope your party is outside! Wish I could come!