First read the account of a day at the games on the page about Roman gladiators. Then, how about putting together a play showing the events of the day? Here’s a list of possible characters:
The slave gladiators
Criminals to be executed (some of them Christian?)
Don’t forget what you learned: in the morning, it’s gladiators fighting animals. Then at lunchtime the condemned criminals are executed. After lunch it’s gladiators fighting other men.