OP here.
Ok, so pizza is enough!
These forums crack me up. On *MOST* party questions, the host asks "Is pizza enough?" and people say "No, you need fruit/hummus/goldish/salad for adults" and on and on. I always thought that was crazy.
Now, we went to a party with just pizza. It was from 11:30-1:30, so exactly lunch time. After an hour of jumping, everyone was pretty hungry.
Food service isn't sufficient.
And yes, there was cake.
At 3, my son was the youngest. Everyone else was 5-9 years old.