Here is a very easy & fun game that we came up with & used for my son's 6 yr birthday party then for a Halloween party...we'll be using it again for my daughter's 6 yr party.
Blow up enough balloons to have one for each child.
Have them rub the balloons on their hair long enough to create enough static electricity that the balloons stick to their heads. Have them start walking around, when their balloon falls off...they're out. Last child with a balloon sticking to them wins. This game took just a matter of minutes but the kids had lots of fun!