Balloon game

So far, here's how it goes:

• There will be 2-10 players in two teams
• They will all wear party hats with a sharpie connected on top so you can draw with the tip of the hat
• The sharpies will come in two colours. One for each team
• In a room, the teams will be separated on opposite sides
• 1-3 white balloons will be thrown in the air and all of the players have to headbutt and therefore mark the balloon/s as much as they can for as long as the game goes
• At the end of the game the marks on the balloon/s will be counted. The team's colour which shows up most on the balloon/s determines the winner.

Gotta figure out what's a good amount of balloons, players, area and time for this game. Oh, and a name.