The aim of this minigame is to run away from your opponents when they are tagged with the Boo. Stay away from them as long as you can to win. In the last 10 seconds a second Boo will come and overtake another player so you'll have to avoid two people for 10 seconds. If you get tagged you'll have to tag someone else.
Personally, I really liked this game. Sometimes I would lose by a big margin and sometimes I will win.