Ball fight
Very fun game that allows participants to release stress and anger
How to play
Turn around with a bag of multi-color plastic ball.
Give all participant one plastic ball each.
Once everyone has a ball, start a speech, very seriously.
Now that you all have a ball, take some time to look at it. This ball represent your knowledge and skills. We are all professionals, we are all serious people. #play14 is serious business. Your boss paid good money so you could come here. We have make sure that he is not disappointed when you go back to work next week.
… build up you speech like that for a while.
Then suddenly just say
Nahhh… we are not here to be serious. Now BAAAAAAAL FIIIIIGHT
… and throw your ball at anyone.
The ball fight can last for a moment, until people get tired.