For my daughter's 6th birthday, she chose an under the sea theme.  As guests arrived they decorated and cut out a paper ball. I made a large Keiko (Orca) whale and we used the paper balls to play pin the ball on Keiko's nose.  My sister-in-law painted different sea creatures on each child's face.  We pretended to be Keiko by bouncing a balloon off of different body parts. Small bean bag creatures were hidden under blue balloons. Guests were given a clue to help them locate their sea creature eg. Look for the white and grey shark named Sharkey.  I colored the color words to help non-readers. We made oceans using screw top water bottles with blue water already in them. Guests chose metallic confetti pieces and sea life beads to put in their oceans.  I then put in some magic potion (mineral water). We played an octopus and fish game. The birthday girl was the octopus in the middle of the playing area. The guests ran past her. If they were tagged, they held hands w/her and became tentacles and helped tag more fish. We ate Keiko cake, drank blue punch with gummie octopus in it. Each child had his/her picture taken next to my husband's scuba gear stuffed to look like a scuba person.  Plastic buckets from Oriental Trading served as favor bags with shells, fish pencils, stickers, and erasers. A good time was had by all.