cupsanddowns is a game where one team tries to turn all the cups upside down and the other team tries to turn them right side up. At the end of the time, whoever has the most their way wins. Simple, inexpensive game that could bring a lot of energy.
Come Together Kids: Mini Marshmallow Shooters (or Pom Pom Poppers) put a balloon over the top half of a stiff plastic cup, with the bottom of the cup removed. Pull of the balloon tie with the pompom inside, and POP!