Trad party games can work with this age group, but you do need to bear in mind that it might be completely unfamiliar territory to most if not all of them. So explain the rules of the game very slowly and carefully to them - don't just expect them to catch on. And keep it very simple.
We also play 'copy cat' - a bit like Simon Says, you say things for them to do and they copy, then you suddenly shout 'copy cat', and they have to sit down with arms and legs crossed ... I know it sounds really boring, but it goes down very well with children this age, IME!
Don't try for elimination games, or even winners -not necessary for this age. And keep the numbers down too.
What space do you have? We borrowed a parachute for a party, and played parachute games, which went down well. Though that was a 4th, and the children had all played parachute games at nursery, so knew what to do.
Hope it goes well.
Oooh - PS - DIY food goes down very well too. Give them biscuits or cakes to decorate. We did desserts too - with jelly, ice-cream, cream, lots of different fruit, plus sauce, sprinkles, choc chips, etc. Not really a game, but very popular.
Can't seem to stop. Really basic sing-song/dance stuff - Ring-a-ring-a-roses, The grand old duke of York, Row row row your boat, Here we go round the mulberry bush ... went down well for us.