My daughter loves this game.
Tie a long piece of ribbon to long balloons. Then tie the string to every child's foot. Everyone runs around trying to pop the others balloons and keep theirs from popping.
Pin the tail on the donkey...use a poster of some sort and stickers with each childs name. That way no one has to worry about tacks.
Do you have a sandbox. Have a little treasure hunt in the sandbox to look for prizes.
Make a treasure map with pictures of furniture and places in the house or yard...each place has a clue to the next clue until they find the treasure. I do this on rainy days sometimes and the treasure box has a little chocolate candy for each child. You use pictures because they kids can't read.