Musical chairs.

Pin the Tail on the Donkey; or Pin the Nose on the Clown

Race while holding an inflated balloon between their knees (appropriate sized balloon please)

Drop the Clothes Pin - place a wide mouth jar on the floor.  As the child stands looking down into the jar, hand each child 3 clothes pins.  From their nose level, see how many clothes pins (one at a time) can they drop into the jar. (3 tries, hence 3 clothes pins).

Need others?  google it

Russian Roulette -  great way to end the party early

Another very simple idea: collect several tins, remove the paper, stick some numbers prealably cut using different colors.

Build a pyramid - you can hide a few sweets under some of the tins if you want - give a child a tennis ball and you guess what's next

For the frisbee, in Migros or Coop you should be able to find one I think..

"What's the time Mr Wolf" more for the younger kids but 5yo usually still like it

Another funny activity to do consists in asking all the kids to sit in a circle, and to ask one of them to start by whispering a word into the ear of the one sitting next to him/her.

If there are some cheeky ones, watch out and you will see some of them covering their ears saying "noooo I can't say that" but still whispering it to the next one who will laugh repeating it to the next one etc...

It's quite entertaining and a good transition before doing another game

Dragon and Prince(ss) game:

The prince(ss) is tied to a chair with 4 ribbons (hands and anckles), the one playing the "dragon" is blindfolded and the other kids have to free the prince(ss), taking off all the ribbons without being catched by the dragon.

That was a pretty awesome game :)

You can go to Parc des Evaux for either :

http://www.evaux.ch/

http://www.evaux.ch/fr/activites/prestations/

Adventure land orFrisbee Golf (free but you can get special frisbees for this at about CHF 4-) or ask HP if they will give you one for free. Or visit Athleticum, they sell them.

http://accrobranchegeneve.com/

At the parc, they have tons of activities and salle for a party:

What about children's picture Bingo ?

How about a Pinata??

Here is how to make a simple one, knowing that all the kids want is to smatch it and get all the sweeties :-))

http://www.youtube.com/watch?v=XE9Y1Of-6VI

I usually give my kids and all their friends a bit of Childrens Nyquil and they tend to sit quietly watching Avatar on nickelodeon