To be able to run around and play the Zombie Game you'll need some way to battery power the Circuit Playground Express. You'll also want some way to attach the Circuit Playground Express board to the outside of your clothing.
For battery power, this 3xAAA battery pack is a good choice. It has an On/Off switch and a nice little belt clip you can use for attaching to clothing. The JST connector plugs right into the Circuit Playground Express.
For actually attaching the Circuit Playground Express, there are various options. This stick pin is one way, but you will need to be careful with the sharp pointy pin.
Attaching it to the board is pretty easy.
Another option is this magnetic holder. It doesn't have any sharp pointy things, but you'll need to be able to put the other side of the holder inside the clothing somehow.
Mounting it is similar to the other pin back.
Remove the backing and stick the one side of the magnet to the back of the Circuit Playground Express.
Pockets also make for convenient battery storage if you can't find a place to clip the battery pack.
OH NO! Losing health! Need to find a Healer fast!