I do a lot of kids parties ranging from age 3 - 16 years.
With that many kids games could be difficult but you could try :-
basically keep it simple.
music wise - for that age range
Current chart/RnB (girls aloud, sugababes, pussycat dolls, take that etc etc)
Party dances (cha cha slide, macarena, saturday night, supeman, music man, fast food song etc etc)
Throw in tracks like Amarillo, Hokey Cokey, S Club - Reach, Cotton Eye Joe etc
Don't forget some Christmas tunes too!