These are a few quick party games you can play to kill time while you wait for the pizza to arrive.

1. Parcel parcel - wrap a present in many layers of paper. Have the kids sit in a circle and pass it from one to the other while you play some birthday music. When you stop the music, whoever is holding the present gets to open one layer of wrapping. Resume the music, stopping every so often to let another child open a layer of wrapping. Whoever opens the final layer gets to keep the present.
   A variation of this for younger kids is to fill each layer with another present so each kid can get one.
2. Simon says - one child, or a parent, plays Simon. The children stand in a group in rows in front of Simon so that each child can see. Simon tells the kids what to do, for instance "Put your hands on your head" or "Jump up and down." When each command is preceeded by the words "Simon says," the kids are supposed to do it. If Simon does not say "Simon says touch your ear," but rather just "Touch your ear," whichever child touches their ear is out.
3. Duck, Duck, Goose - This simple game is surprisingly exciting for younger kids - ideal for ages 3-6.
4. Toss up - Make a hat from plastic bowl and use a rubber band for a chin strap to hold it on the children's head. Pair off the kids. One wears the hat and the other has to toss koosh ball beanbag into hat. The first team to catch it wins.