String up ring doughnuts at head height, then tie everyone's hands behind their backs. On 'go' all have to eat one each - first one to finish is the winner. We did this for our son's 4th in the summer and strung them at two heights from the washing line - some for adults and some of the mini doughnuts for the little ones. We had a few goes, and everyone loved it!
Or make a 'web' around the room out of as many lengths of wool as there are players - one colour each makes it easier if you want. Loop them round each other, back and forwards, up and down, round and round. Hide one end of each somewhere in the room, and tie a prize on one. Give each player one of the other ends, and then stand back and watch them try and untangle and wind up their wool, stepping over and under and round etc until they reach their various ends. You can string things on the wool as you go, for them to collect - that way they can't cheat if they see where their 'end' goes!! It takes a lot of setting up, but it's well worth it. (Also, it has to be the first game if you want to use the room.)