What does that mean!
It sounds like they want you to do some engaging, drilling, elicitation type activities. I think you can consider review to be OK, even though they said 'something new' everyday.
I can see where you'd be frustrated but don't be. I think you can have fun and educate even in that short bit of time. Unfortunately it will be very teacher centered and doesn't provide much learner time.
Is that right? several hundred kids? or is that classes per week?
I think songs and chants would be great. It sounds very 'show' like. Try to think about some children's educational programs you have watched. They are loaded with ideas.
You might really benefit from a side-kick. Maybe try using a puppet or several for that matter. Give them characters (one is sad, one is shy, one is mean, one is always unsure, and so on.) That will really help to give you someone to interact with. Consider it team teaching.
Also, the kids love it when the puppets fight.
