Our Daughters senior class has a party on Grad night. They hire casino tables. The kids love Texas hold em.. I bet some of the dads could be the dealers..
Bingo is something that the kids played all night long. They are given a bag of m&m's or skittles to use as their dobs. Each game has a winner that wins $5. Once an hour there is a game that the winner wins $20.
Rock band can be set up. Karaoke is still popular.
Baby pictures are fun. Have the kids bring their baby picture. The kids have to guess who they are, the person that guesses the most wins.
We also had Caricature artist to draw the kids.
We had a roving photographer (junior yearbook photographer) who took candid s all night. At 2:00 am, I took the photo card to Walgreens and they printed doubles of all of them in an hour.. I was then able to lay them out on a table and the kids took home whatever photos they wanted. At the end of the night. I had a couple of Disc made, so that the class President could hold onto it for their future class reunions.
I also suggest you have at least 1 physical thing for the kids to do. We hired a group to bring the big Sumo Wrestling outfits so the kids (guys) could let off some steam.
You could do contests.. Most flexible, Limbo, largest hands etc.. give out prizes.